Fluid distributor, burner device, gas turbine engine, and cogeneration system

ABSTRACT

A fluid distributor includes a first feed port for feeding fuel gas into a main fuel flow path, a feed path for feeding the fuel gas inside a gas flow path to the first feed port, and distributedly into a pilot fuel flow path so as to increase the distribution ratio of the fuel gas to the first feed port according to an increase in an overall feed flow rate of the fuel gas from the gas flow path to a feed path and, inversely, to decrease the distribution ratio of the fuel gas to the first feed port according to a decrease in the overall feed flow rate. A plurality of fluid distributors are disposed in the main fuel flow path and pilot fuel flow path distributedly in the peripheral direction to constitute a gas feed means.

TECHNICAL FIELD

This invention relates to a burner apparatus comprising an inner tubedefining a second channel and an outer tube defining a first channelsurrounding the inner tube, air supplying means (an example ofoxygen-containing gas supplying means) for supplying air (an example ofoxygen-containing gas) to the first channel and the second channel, andgas supplying means for supplying fuel gas to the first channel and thesecond channel, either the first channel or the second channel beingused as a main combustion channel and the other being used as a pilotcombustion channel, the main combustion channel and the pilot combustionchannel receiving the supply of fuel gas for combusting it. Theinvention relates also to a gas turbine engine including said burnerapparatus and a co-generation system including the gas turbine engine.The invention further relates to a fluid distributor for use in such gasturbine engine including the burner apparatus, the co-generation systemincluding the gas turbine engine, the burner apparatus, the distributorbeing disposed across three channels including first and second channelsthrough which a first fluid such as air is caused to flow and a gaschannel (an example of fluid channel) through which a second fluid suchas fuel gas is caused to flow, so that the distributor distributes thefuel gas inside the fluid channel between the first channel and thesecond channel.

BACKGROUND ART

The burner apparatus described above is used as a burner apparatus for agas turbine engine used in a co-generation system or a burner apparatusused for an incinerator. With this burner apparatus, it is necessary notonly to adjust the flow amounts of the fuel gas to be fed to the maincombustion channel and the pilot combustion channel, in accordance withincrease/decrease in the combustion load for assuring good combustionwith maintaining appropriate equivalent ratio for the main combustionchannel and the pilot combustion channel, but also to adjust the flowamounts of the air to be fed to the main combustion channel and thepilot combustion channel.

Conventionally, in order to make the adjustment of the flow amounts ofthe fuel gas to the main combustion channel and the pilot combustionchannel, a flow-amount adjusting valve was provided in a fuel gas supplyline to the main combustion channel and in a further fuel gas supplyline to the pilot combustion channel, respectively, so as to make theadjustment of the flow amounts of the fuel gas to the main combustionchannel and to the pilot combustion channel, independently of eachother.

However, according to the prior art described above, as the adjustmentof the supply amount of fuel gas to the first channel and that to thesecond channel in accordance with the combustion load are effectedindependently of each other, the adjustment operation was troublesome.

Further, in the case of the burner apparatus of the above type whicheffects pilot combustion and main combustion, the supply amounts of fuelgas respectively to the main combustion channel and to the pilotcombustion channel are reduced in association with decrease in thecombustion load relative to a rated combustion load. In association withsuch decrease in the supply amount, it is necessary to increase thesupply amount to the pilot combustion channel to maintain stable pilotcombustion.

Moreover, with such burner apparatus, it is especially needed to mixfuel gas and air in a reliable manner inside the first channel in whichthe main combustion is effected. For, if they are not mixed well, thereoccurs unevenness in the equivalent ratio in the fuel-air mixturecontaining the fuel gas and the air in a mixed state, so that in aregion of a higher equivalent ratio high-temperature combustion willoccur, resulting in increase in NOx generation amount.

According to the conventional burner apparatus, as shown in FIG. 44, asupply line provided within the combustion channel for receiving fuelgas supply defines a plurality of supply openings arranged in dispersionfor discharging the fuel gas through the plural openings to thecombustion channel. In this case, the plural supply openings are openedon the downstream side in the direction of air flow in the combustionchannel, so as to discharge the fuel gas in the same direction as theair. With this construction, by dispersing the supply of fuel gas to thecombustion channel, the apparatus was designed to improve the mixingdegree between the air and the fuel gas G.

With such conventional burner apparatus, in order to achieve uniformityin the supply of fuel gas to the combustion channel by providing aplurality of supply openings for one supply line, it is desirable forthe supply openings to be provided as many as possible. However, as thetotal amount of fuel gas to be supplied to the combustion channel isdetermined in advance, as the number of the supply openings isincreased, it becomes necessary to reduce the opening area of eachsupply opening.

As a result, there occurs increased pressure loss at the supplyopenings. Then, in order to discharge a predetermined amount of the fuelgas, it becomes necessary to supply the fuel gas with an increasedpressure into the supply line, thus requiring disadvantageous physicaland capacity enlargement of the gas supplying means for the burnerapparatus.

Incidentally, the equivalent ratio represents an amount indicative ofconcentration aspect of the fuel-air mixture of the fuel and thecombustion air and this is defined herein as follows.

equivalent ratio=(fuel concentration/air concentration)/(fuelconcentration/air concentration)st

Each concentration is represented in the mole value, and (fuelconcentration/air concentration)st is a theoretical fuel-air ratio. Thistheoretical fuel-air ratio is the concentration ratio between an amountof fuel and air needed for complete oxidation of that amount of fuel.

DISCLOSURE OF THE INVENTION

Therefore, an object of the present invention is to provide a fluiddistributor which allows easy adjustment of the supply amounts of fuelgas to the main combustion channel and the pilot combustion channeldepending e.g. on the combustion load and which also allows increase inthe distribution ratio of the supply amount to the pilot combustionchannel in association with decrease in the supply amount, as well as apreferred burner apparatus using the distributor, a gas turbine engineincluding the burner apparatus and a co-generation system including thegas turbine engine.

A further object of the present invention is to provide a burnerapparatus which achieves reduced pressure loss occurring when the fuelgas is supplied to the combustion channel and which also achievessuperior mixing of the fuel gas and the air.

In order to accomplish the above-noted objects, the burner apparatusaccording to the present invention is characterized in that said gassupplying means includes a plurality of fluid distributors arranged indispersion in a peripheral direction of the main combustion channel andthe pilot combustion channel, each fluid distributor including a firstsupply opening for supplying the fuel gas into the main combustionchannel, a supply line for supplying the fuel gas present inside the gaschannel to the first supply opening, and distributing means incorporatedin the supply line for distributing the fuel gas into the pilotcombustion channel so that the distribution ratio of the fuel gas to besupplied to the first supply opening is increased in response toincrease in a total supply amount of the fuel gas from the gas channeland conversely the distribution ratio of the fuel gas to be supplied tothe first supply opening is decreased in response to decrease in thetotal supply amount.

Further, the burner apparatus according to the present invention, inaddition to the burner apparatus construction described above, isfurther characterized in that the first channel is used as the maincombustion channel and the second channel is used as the pilotcombustion channel.

That is to say, the first channel used as the main combustion channelreceives air from the air supplying means and receives also the fuel gaspresent inside the gas channel via the gas supplying means, so that thefuel-air mixture of the air and the fuel gas is produced therein andthis fuel-air mixture is ignited to provide main combustion of thefuel-air mixture. On the other hand, the second channel used as thepilot combustion channel receives the air from the air supplying meansand receives also the fuel gas present inside the gas channel via thegas supplying means, so that the fuel-air mixture of the air and thefuel gas is produced therein and this fuel-air mixture is ignited toprovide pilot combustion of the fuel-air mixture.

And, the gas supplying means comprises the fuel distributors adapted forsupplying the fuel gas to the main combustion channel and the pilotcombustion channel and adapted also for distributing the fuel gaspresent inside the gas channel between the main combustion channel andthe pilot combustion channel. That is, as the fluid distributor includesthe distributing means incorporated within the supply line for supplyingthe fuel gas inside the gas channel to the main combustion channel viathe first supply opening, the distributor distributes the fuel gas tothe main combustion channel and also to the pilot combustion channel.Further, the distributor is constructed so that the distribution ratioof the fuel gas to be supplied to the first supply opening is increasedin response to increase in a total supply amount of the fuel gas fromthe gas channel and conversely the distribution ratio of the fuel gas tobe supplied to the first supply opening is decreased in response todecrease in the total supply amount.

Therefore, it is not necessary to adjust the supply amount of the fuelgas to the main combustion channel and the supply amount of the fuel gasto the pilot combustion channel respectively and independently of eachother. Rather, adjustment of the distribution ratio of the fuel gasbetween the main combustion channel and the pilot combustion channel inaccordance e.g. with variation in the combustion load can be done simplyby adjustment of the total supply amount of the fuel gas to the fuel gaschannel. Moreover, with the burner apparatus according to the presentinvention, in association with decrease in the total supply amount ofthe fuel gas at the time of low combustion load, the supply amount ofthe fuel gas to the pilot combustion channel is increased to providestable pilot combustion; whereas, in association with increase in thetotal supply amount of the fuel gas at the time of rated combustionload, the supply amount of fuel gas to the main combustion channel isincreased, thereby to uniformly supply the fuel gas to the maincombustion channel and the pilot combustion channel so as to realize lowNOx combustion with lean fuel-air mixture. As a result, with such simpleconstruction, it is possible to achieve higher efficiency over a widecombustion load range.

In addition, since a plurality of such fluid distributors for supplyingthe fuel gas to the main combustion channel and the pilot combustionchannel are distributed along the peripheral direction of the maincombustion channel and the pilot combustion channel, the fuel gas may besupplied in distribution in the peripheral direction into the maincombustion channel and the pilot combustion channel, thereby to providegood mixing between the fuel gas and air inside the main combustionchannel and the pilot combustion channel. As a result, uniformity of thefuel-air mixture can be obtained.

Also, with the burner apparatus of the present invention, in the outerfirst channel and the inner second channel, either combustion channelmay be used as the main combustion channel. However, by using the outerfirst channel as the main combustion channel and the inner secondchannel as the pilot combustion channel, it becomes possible to increasethe fuel gas in the inner pilot combustion channel at the time of lowcombustion load for increasing the distribution ratio of the fuel gasfor the pilot combustion channel, thereby to provide stable pilotcombustion in the pilot combustion channel.

Moreover, in this case of using the outer first channel as the maincombustion channel and the inner second channel as the pilot combustionchannel, it is possible to insert a gas tube defining the gas channelinto the inner tube defining the second channel as the pilot combustionchannel, whereby the gas channel, the pilot combustion channel and themain combustion channel are formed in this order from the inner side tothe outer side, and the supply line for supplying the fuel gas from thegas channel to the first supply opening is formed to transverse thepilot combustion channel. Hence, the distributing means can be formedeasily at this portion where the supply line(s) transverses the pilotcombustion channel.

On the other hand, if the outer first channel is used as the pilotcombustion channel and the inner second channel is used as the maincombustion channel, it becomes possible to reduce the length of anignition plug which is to be inserted into the pilot combustion channelfrom the outside.

Incidentally, as each of the inner tube and outer tube described above,a tube having a circular cross section may be employed of course.However, an angular tube having a polygonal cross section can beemployed instead for example.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is furthercharacterized in that in the distributing means includes, in the supplyline, a second supply opening for discharging the fuel gas into thepilot combustion channel in a direction normal to the flowing directionof the air inside the pilot combustion channel and a communication linefor receiving the fuel gas discharged from the second supply opening andguiding the gas into the first supply opening, and at a position opposedto the second supply opening and spaced apart by a predetermineddistance in the discharging direction of the second supply opening,there is provided a receiving opening of the communication line as to beopen toward the second supply opening.

That is, with the burner apparatus of the present invention, the gastube is provided adjacent the pilot combustion channel and its gaschannel includes the second supply opening for discharging the fuel gasto the pilot combustion channel and the receiving opening is provided atthe portion of the inner tube opposed to the second supply opening viathe pilot combustion channel and to which the discharge of the fuel gasis oriented.

Namely, the fuel gas supplied into the gas channel is discharged throughthe second supply opening toward the receiving opening to the pilotcombustion channel.

And, in a second gas supply area where the fuel gas discharged in thepilot combustion channel is present, a portion of the fuel gastransversing the pilot combustion channel will be carried away by theair current of the pilot combustion channel to the downstream side ofthis pilot combustion channel while the rest of the fuel gas will becarried across the air current of the pilot combustion channel to reachthe first supply opening via the receiving opening and will eventuallybe supplied to the main combustion channel.

More particularly, of the fuel gas discharged from the second supplyopening into the pilot combustion channel, its portion introduced intothe communication line from the receiving opening is guided via thecommunication line to the first supply opening to be supplied into themain combustion channel, whereas the remaining portion of the fuel gasnot introduced into the receiving opening is supplied to the pilotcombustion channel. And, the greater the supply amount and the higherthe speed of the fuel gas discharged from the second supply opening, thehigher the ratio of the portion of the fuel gas discharged from thesecond supply opening to enter the receiving opening. As a result, thegreater the supply amount of the fuel gas, the greater the distributionratio of the fuel gas for the first supply opening, that is, for theside of the main combustion channel. Conversely, the smaller the supplyamount of the fuel gas, the smaller the distribution ratio of the fuelgas for the side of the main combustion channel.

Therefore, in the burner apparatus, by simply providing the secondsupply opening and the communication line having the receiving opening,with such simple construction, the distributing means of the fluiddistributor may be provided.

Further, the amount of air flowing in the pilot combustion channel isnormally contained within a predetermined range, so that e.g. thepositional relationship between the second supply opening and thereceiving opening is fixedly established. Hence, by increasing thesupply amount of the fuel gas from the second supply opening, the ratiobetween the amount of the fuel flowing to the downstream side of thepilot combustion channel and the amount of the fuel to be supplied tothe pilot combustion channel may be reversibly varied in associationwith increase/decrease in the fuel supply amount.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterizedfurther in that said fluid distributor includes a plurality of saidfirst supply openings distributed in the main combustion channel in adirection away from the pilot combustion channel.

That is, by using the fluid distributors mounted inside the maincombustion channel with the plurality of first supply openingsdistributed in the direction away from the pilot combustion channel,i.e. in the radial direction of the first and second channels, evengreater uniformity of the fuel-air mixture can be obtained, thereby toreduce the equivalent ratio for NOx generation reduction by leancombustion and also for stabilization of the lean combustion.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the supply line is provided in correspondence to each ofthe plurality of first supply openings.

That is to say, as the supply line is provided in correspondence to eachof the plurality of first supply openings, in comparison with e.g. acase in which the fuel gas is supplied to the plurality of first supplyopenings via one supply line, it is possible to reduce the pressure losswhich would occur for supplying the fuel gas uniformly from theplurality of first supply openings.

Therefore, it becomes possible to further improve the uniformity of themixture between the air and the fuel gas inside the main combustionchannel while reducing the pressure loss, so that the pressure lossassociated with the fuel gas supply may be reduced while maintaining thelow NOx generation performance.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the fluid distributor is constructed such that the supplylines corresponding to the plurality of first supply openings are formedin a plate-like member disposed within the main combustion channel withits plate surface oriented along the air flow direction.

That is to say, the plurality of supply lines are formed in theplate-like member disposed within the main combustion channel inalignment with the air flow direction, so that the plate-like memberforming the supply line is disposed along the air flow direction. Hence,in spite of the provision of the plurality of supply lines, this hardlyinterferes with the air flow.

Moreover, as the plurality of supply lines are formed together as agroup within the plate-like member, the handling such as assembly iseasy.

Therefore, it is possible to supply the fuel gas uniformly relative tothe air while maintaining good air flow in the main combustion channel.Further, in spite of the provision of the plurality of supply lines, thehandling such as maintenance, assembly or the like is improved.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the plate-like members of the plurality of fluiddistributors are disposed with each plate surface thereof oriented alongthe spiral direction of the main combustion channel so as to act as afin of a swirler for providing a swirling force to the supplied air.

In such burner apparatus, as the swirler provides the swirling force tothe air to be supplied to the main combustion channel to enhance themixing degree between the air and the fuel gas, the lean combustion cantake place effectively. In this regard, attention was directed to thefact that the fluid distributor for distributing the fuel gas inside thegas channel to the main combustion channel and the pilot combustionchannel includes the plate-like member forming the first supply openingsand the supply lines. Then, by disposing this plate-like member inalignment with the spiral direction of the main combustion channel, thisplate-like member can constitute a swirler fin. Hence, the fluiddistributor and the swirler can share the same member.

Accordingly, while achieving the improved uniformity in the mixingperformance, it has become possible to achieve simplification and costreduction of the construction.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that at a portion of the main combustion channel more downstreamthan the first supply openings in the air flow direction, there isprovided a swirler for providing a swirling force to the fuel-airmixture of the air and the fuel gas in the spiral direction of the maincombustion channel.

In the burner apparatus of the present invention, at the portion of themain combustion channel on the downstream of the fluid distributors, theswirler for improving flame stability of the main combustion may beprovided for providing a swirling force to the fuel-air mixture of theair and the fuel gas. So that, the orientation of the first supplyopening may be simple. Moreover, without disturbing the air flow at thefirst supply opening, the fuel-air mixture may be swirled for improvingthe flame stability of the main combustion.

Accordingly, it has become possible to further improve the leancombustion performance.

Further, the burner apparatus of the present invention is characterizedin further that the first supply opening is disposed, in the maincombustion channel, with an orientation for discharging the fuel gastoward more upstream side of the flow direction of the oxygen-containinggas than the direction normal to the flow direction of theoxygen-containing gas.

That is, by disposing the first supply opening with such orientation fordischarging the fuel gas toward more upstream side of the flow directionof the air than the direction normal to the air flow direction, the fuelgas is to be discharged against the flow of the air in the maincombustion channel. As a result, the fuel gas and the air will collideagainst each other for providing natural stirring and mixing of the fuelgas in the air and will be diffused in both the radial and peripheraldirections of the main combustion channel.

In this way, with the burner apparatus of the present invention, forachieving the uniform discharge of the fuel, it is not needed to providea great number of first supply openings of a small diameter. Instead,this is possible by increasing the aperture diameter of the first supplyopening. Therefore, no significant pressure loss occurs in associationwith the supply of the fuel, and the mixing degree between the fuel gasand the air may be enhanced by utilizing the air flow.

Moreover, in order to allow the fuel gas to be discharged from the firstsupply opening, this is possible by providing the fuel gas with apressure overwhelming the pressure of the circulating air. In thisregard, this air pressure is of such magnitude as hardly affects thedischarging of the fuel gas. Accordingly, it is not necessary to enlargethe gas supplying means for supplying the fuel gas. Instead, the fuelgas may be mixed reliably with a simple device. Consequently, it becomespossible to provide a burner apparatus which achieves further reductionin NOx generation amount.

And, in combination with the fluid distributor used as the gas supplyingmeans in the present invention, in the distributing means, in supplyingthe fuel gas through the route from the second supply opening, the pilotcombustion channel, the receiving opening, the first supply opening tothe main combustion channel, as the first supply opening is configured,as described above, to discharge the fuel gas toward the upstream sidein the air flow direction thereby to reduce the pressure loss throughthe first supply opening, the fuel gas discharged from the second supplyopening into the pilot combustion channel may be received efficientlyinto the receiving opening communicated with the first supply openingwith the reduced pressure loss. Thus, the mechanism can be realized witha relatively simple construction.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the first supply opening is disposed, in the maincombustion channel, with an orientation for discharging the fuel gas ina direction opposing to the air flow direction.

That is to say, in the case of this construction in which the firstsupply opening is configured to discharge the fuel gas in the directionopposing to the flow direction of the air, the relative speed betweenthe fuel gas and the air discharged is maximized, so that the mixingdegree of the fuel-air mixture in the main combustion channel can bemaximized as well.

Further, the burner apparatus of the present invention is characterizedin further that the main combustion channel includes a mixing promotingmember against which the fuel gas discharged from the first supplyopening into the main combustion channel is collided to be diffused inthe main combustion channel or the pilot combustion channel includes amixing promoting member against which the fuel gas discharged from thesecond supply opening for supplying the fuel gas into the pilotcombustion channel is collided to be diffused in the pilot combustionchannel.

Further, in the case of the apparatus being combined with the fluiddistributor as the gas supplying means in the present invention, theburner apparatus of the present invention is characterized in that theapparatus includes a mixing promoting member against which the fuel gasdischarged from the first supply opening into the main combustionchannel is collided to be diffused in the main combustion channel.

That is to say, by providing such mixing promoting member, it ispossible to collide the fuel gas discharged from the supply openingagainst the mixing promoting member to be diffused thereby, so that thefuel-air mixture may be rendered further uniform in the main combustionchannel or in the pilot combustion channel.

Moreover, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the mixing promoting member comprises a ring-like memberdisposed along the peripheral direction of the main combustion channelor the pilot combustion channel and having a plate face along thedischarging direction of the fuel gas of the plurality of first supplyopenings or second supply openings distributed along the peripheraldirection.

That is to say, the mixing promoting member can be provided as aring-like member disposed continuously or intermittently across theplurality of first or second supply openings arranged in the peripheraldirection of the main combustion channel or the pilot combustionchannel. Namely, by causing the fuel gas discharged from the pluralityof supply openings arranged in the peripheral direction to collideagainst the plate surface of this ring-like mixing promoting member, itis possible to diffuse the fuel gas at least in the peripheral directionof the combustion channel.

Further, if the distance between the mixing promoting member and therespective supply openings is too small, this will increase dischargingresistance of the fuel gas. Conversely, if the distance is too large,the diffusion of the fuel gas will not be able to take placeeffectively. Therefore, this distance will be set appropriately, takinginto consideration the discharging resistance and the diffusioncondition.

Further, in the case of the combination with the fluid distributor asthe gas supplying means of the present invention, this mixing promotingmember is provided for the first supply openings of the main combustionchannel to be utilized for diffusion of the fuel in the main combustionchannel. And, by providing the mixing promoting member in the maincombustion channel, it is not needed to provide a great number of firstsupply openings of a small diameter. Instead, it is possible to enlargethe aperture diameter of the first supply opening. Therefore, nosignificant pressure loss occurs in association with the supply of thefuel, and the mixing degree between the fuel gas and the air may beenhanced by utilizing the air flow. Further, with the reduction of thepressure loss at the first supply openings, the fuel gas discharged fromthe second supply opening into the pilot combustion channel may beeffectively received in the receiving opening communicated with thefirst supply openings with the reduced pressure loss. In this manner,the mechanism can be realized with a relatively simple construction.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that there is provided a second shielding member for adjustingan inflow amount of the oxygen-containing gas, for the second gas supplyarea extending from the upstream side of the second supply opening inthe flow direction of the oxygen-containing gas via the second supplyopening of the pilot combustion channel to the receiving opening.

That is to say, by providing the second shielding member on the upstreamside of the second supply opening of the second channel as proposed bythis construction, it becomes possible to restrict inflow of the airinto the second gas supply area from the upstream side of the pilotcombustion channel, thereby to appropriately adjust the inflow amount ofthe air into the second gas supply area. As a result, in the second gassupply area, the ratio of the fuel gas reaching and entering the secondsupply opening may be adjusted appropriately, so that the distributionratio of the fuel gas for the main combustion channel may be adjusted tosuit the operation condition of the burner apparatus.

Further, as this second shielding member restricts the air entering thesecond gas supply area from the upstream side, by enlarging the diameterof the second supply opening, the discharging speed of the fuel gas maybe reduced for reducing the pressure loss of the fuel gas at the secondsupply opening.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the second shielding member comprises a member disposedacross at least a portion of the second gas supply area upstream in theflow direction of the oxygen-containing gas.

That is, as the second shielding member, it is possible to employ a e.g.flat-plate-like or curved-plate-like member which is disposed across atleast a portion of the second gas supply area upstream in the air flowdirection and which has a plate surface extending, in e.g. the secondchannel upstream in the air from of the second supply opening, from awall portion of the gas channel to a wall portion of the main combustionchannel, in a direction normal to or inclined relative to the air flowdirection.

In this case too of providing such plate-like member described above, itis possible to restrict inflow of the air from the upstream side of theair flow direction in the pilot combustion channel, for the second gassupply area where the fuel gas is supplied in the pilot combustionchannel, thereby to appropriately adjust the inflow amount of air intothis second gas supply area, so that the distribution ratio of the fuelgas between the main combustion channel and the pilot combustion channelmay be adjusted to suit the operation condition of the burner apparatus.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the second shielding member comprises a tubular memberwhich surrounds a portion of the second gas supply area.

That is to say, the second shielding member may be provided for exampleas a cylindrical or angular tubular member which extends from the outerperiphery of the second supply opening toward the main combustionchannel to surround a portion of the second gas supply area.

Further, in the second gas supply area surrounded by such tubularmember, the inflow of the air from the upstream side may be restrictedreliably and also the discharging direction of the fuel gas may beadjusted with high precision. Also, at the terminal end of the tubularmember of the pilot combustion channel, there is formed a slit exposedto the air flow of the pilot combustion channel in the second gas supplyarea. Accordingly, by appropriately setting the width of this slitthrough adjustment of the height of this tubular member in the axialdirection interconnecting the first and second supply openings, theinfluence of the air flowing into the slit on the flow of the fuel gasmay be precisely adjusted to be advantageous and the distribution ratioof the fuel gas between the main combustion channel and the pilotcombustion channel may be adjusted to further suit the operationcondition of the burner apparatus.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the second shielding member defines an opening foradjusting the inflow condition of the oxygen-containing gas to thesecond gas supply area.

Namely, by defining at least one circular, slit-like or polygonalopening in the plate-like member as the second shielding member asproposed by this construction, the inflow amount or distribution of theinflow air as the inflow condition of the air into the second gas supplyarea may be adjusted.

That is to say, the air will flow via the opening through the plate-likemember and this through air will flow into the second gas supply area.Hence, by appropriately forming the opening, it is possible to adjustthe ratio of the fuel gas passing the second gas supply area and flowingthrough the receiving opening and the first supply openings into themain combustion channel to suit the operation condition of the burnerapparatus.

Further, the burner apparatus of the present invention is characterizedin further that discharging resistance of the fuel gas from each saidfirst supply opening due to passage of the oxygen-containing gas is setso as to increase as being distant from the pilot combustion channel.

That is, according to this construction, the main combustion channelincludes the plurality of first supply openings for the fuel gasdiffused in the direction away from the pilot combustion channel, anddischarging resistance of the fuel gas from each said first supplyopening due to passage of the oxygen-containing gas is set so as toincrease as being distant from the pilot combustion channel. With this,when the supplying pressure of the fuel gas is higher at the time of therated combustion load, at all of the first supply openings, the fuel gasis supplied to the main combustion channel, overcoming the dischargingresistance. Conversely, when the supplying pressure of the fuel gas islow at the time of low combustion load, at those first supply openingsof the main combustion channel which opening are disposed away from thepilot combustion channel and provides higher discharging resistance, thedischarging of the fuel gas is inhibited by the discharging resistance,so that the fuel gas is discharged to the main combustion channel onlyfrom those first supply openings disposed close to the pilot combustionchannel.

Therefore, at the time of rated combustion load, the fuel gas may besupplied entirely in the width direction of the main combustion channel(the direction distant from the pilot combustion channel) to provide therated combustion load operation with high combustion load. Conversely,in the case of the low combustion load operation, the fuel gas may besupplied more to the portion of the main combustion channel close to thepilot combustion channel than the case of the rated combustion load.Further, in combination with the fluid distributor as the gas supplyingmeans of the present invention, the fuel gas for the main combustion maybe ignited and combusted in the pilot combustion under advantageousconditions. Hence, high efficiency is obtained over the wide combustionload range.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the setting of the discharging resistance of the fuel gasis done such that a discharging angle for the fuel gas at each saidfirst supply opening toward the upstream side in the flow direction ofthe oxygen-containing gas in the main combustion channel is decreased asbeing distant from the pilot combustion channel.

That is, according to this construction, the discharging angle for thefuel gas at each first supply opening toward the upstream side in theflow direction of the air in the main combustion channel is decreasedcontinuously or stepwise as being distant the pilot combustion channel.With this, those first supply openings disposed away from the pilotcombustion channel rather than the first supply openings disposedadjacent the pilot combustion channel will discharge the fuel gasagainst the flow of the air, thus the discharge gas will experiencegreater discharging resistance from the air flow. Hence, as the burnerapparatus having this construction is capable of supplying the fuel gasto the portion adjacent the pilot combustion channel more at the time oflow combustion load than at the time of the rated combustion load, sothat the fuel gas for the main combustion may be ignited and combustedin the pilot combustion under the advantageous condition.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the setting of the discharging resistance of the fuel gasis done such that the discharging direction of the fuel gas from theplurality of first supply openings is set to be more upstream than thedirection normal to the flow direction of the oxygen-containing gas inthe main combustion channel and also that the opening area of each saidfirst supply opening is increased as being distant the pilot combustionchannel.

That is to say, according to the present construction, by setting thedischarging direction of the fuel gas from the plurality of first supplyopenings to be more upstream than the direction normal to the flowdirection of the air in the main combustion channel, at each firstsupply opening, the fuel gas will experience discharging resistance inthe flow direction of the air, and the greater the opening area of thefirst supply opening, the greater this discharging resistance of thefuel gas.

Then, by adapting the opening area of the first supply openings tocontinuously or stepwise increase as being distant the pilot combustionchannel, discharging resistance for the fuel gas may be set greater forthose first supply openings disposed away from the pilot combustionchannel than the first supply openings disclosed closer to the pilotcombustion channel. Therefore, with the burner apparatus having thisconstruction, more of the fuel gas may be supplied to the portion closeto the pilot combustion at the time of low combustion load than at thetime of the rated combustion load. Hence, the fuel gas for the maincombustion may be ignited and combusted under the advantageous conditionin the pilot combustion.

Further, the burner apparatus of the present invention is characterizedin further that the first supply openings are configured to supply thefuel gas into the first channel along the direction of the maincombustion channel distant from the pilot combustion channel; and afirst shielding member is provided for preventing inflow of the air fromthe upstream side along the flow direction of the air in the firstchannel, for a first gas supply area formed by the fuel gas suppliedfrom the first gas supply openings inside the main combustion channel.

That is, by providing the burner apparatus of the invention with thefirst shielding member for preventing inflow of the air from theupstream side in the air flow direction of the main combustion channel,i.e. along the axial direction of the inner tube and outer tube, for thegas supply area where the fuel gas is supplied in the main combustionchannel, the fuel gas supplied along the direction away from the innertube and the outer tube will experience of less influence form the airflow, so that the gas will be readily diffused toward the outer side ofthe main combustion channel relative to the pilot combustion channel.For this reason, the mixing between the fuel gas and the air inside themain combustion channel will take place uniformly, thereby to achievelow NOx generation in the main combustion.

If the fuel gas can be readily diffused to the outer side of the maincombustion channel, the discharging speed of the fuel gas at the firstsupply openings may be reduced. Then, the supply pressure of the fuelgas may be reduced, for example. As a result, the pressure loss in thegas supplying means may be reduced and the such devices as the gassupplying means may be formed compact.

And, in combination with the fluid distributor as the gas supplyingmeans in the present invention, in the distributing means, in supplyingthe fuel gas through the route from the second supply opening, the pilotcombustion channel, the receiving opening, the first supply opening tothe main combustion channel, as the first shielding member is providedas above for reducing the pressure loss at the first supply opening, thefuel gas discharged from the second supply opening into the pilotcombustion channel may be received efficiently into the receivingopening communicated with the first supply opening with the reducedpressure loss. Thus, with such very simple construction of the gassupplying means, the combustion condition of the main combustion in themain combustion channel and the combustion condition in the pilotcombustion in the pilot combustion channel may be set appropriately.

Moreover, if the first shielding member assures the diffusion of thefuel gas into the main combustion channel, the equivalent ratio of themixture of the air and the fuel gas will be rendered constant at anyposition in the main combustion channel. As a result, such inconvenienceas occurrence of local high-temperature combustion can be avoided, sothat the combustion can take place with reduced NOx generation.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that a ratio (c/e) between a distance (c) between the openingcenter of the first supply opening and the first shielding memberdefined along the air flow direction of the main combustion channel andan opening width (e) of the first supply opening defined in saiddirection is set to be greater than or equal to 0.5 and smaller than orequal to 1.5.

That is to say, the distance between the first supply opening and theshielding member is specified within a fixed range. Namely, the settingof the ratio (c/e) to 0.5 means that the fuel gas first supply openingis disposed adjacent the shielding member. On the other hand, thesetting of the ratio (c/e) to 1.5 means that the distance between thefirst shielding member and the edge of the first supply opening is equalto the opening width of the fuel supply opening in the axial directionof the pilot combustion channel, in other words, in the axial directionof the inner tube and the outer tube.

By setting the distance between the first supply opening and theshielding member as described above, it is possible to minimize theinfluence of the air on the fuel gas supplied from the first supplyopening into the main combustion channel. Accordingly, the uniformity ofthe fuel gas to the main combustion channel will be further assured andfurther reduction in NOx generation in the main combustion can beobtained.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the first shielding member comprises a member which extendsin the direction where the main combustion channel extends away from thepilot combustion channel, one first end of the first shielding member onthe side adjacent the first supply opening has a width (a) along theperipheral direction of the main combustion channel, the other secondend has a width (b) along the peripheral direction, the first supplyopening has a width (d) along the peripheral direction; and a ratio(a/d) between said width (a) and said width (d) is greater than or equalto 1 and smaller than or equal to 3, and a ratio (b/d) between saidwidth (b) and said width (d) is greater than or equal to 0 and smallerthan or equal to 2.

That is to say, the first shielding member extends, in the maincombustion channel, in the direction away from the pilot combustionchannel, i.e. in the radial direction of the inner tube and the outertube and this member has the first and second ends as its opposed endsin the extending direction. And, this construction defines therelationships between the widths of these opposed ends and the openingwidth of the first supply opening.

Namely, of the two ends of the first shielding member, the one end onthe side adjacent the first supply opening is provided as the first end,and the other end apart from the first supply opening is provided as thesecond end, and the width of the first end in the peripheral directionof the main combustion channel is specified to be one to three timesgreater than the opening width of the first supply opening in theperipheral direction. That is to say, by setting the width of the firstend greater than the width of the first supply opening, direct collisionof the air against the fuel gas discharged from the first supply openingto the main combustion channel is avoided. With this, of the velocity ofthe discharged fuel gas, its radial velocity component can be maintainedwell in particular, whereby the uniform mixing effect of the fuel gas inthe radial direction is improved.

On the other hand, the width of the second end along the peripheraldirection is set to be greater than or equal to 0 or smaller than orequal to 2 times greater than the opening width of the first supplyopening in the same direction. The fuel gas discharged from the firstsupply opening into the main combustion channel will flow outward in theradial direction with more or less diffusion. However, due to thedischarging speed of the fuel gas or various conditions such as theradial size of the main combustion channel, there will occur adifference in the diffusion conditions in the fuel gas which has reachedthe vicinity of the second end. Namely, by varying the amount of the airto collide against the fuel gas depending on the degree of diffusion,the equivalent ratio of the fuel-air mixture will be rendered constantthrough the entire main combustion channel.

Needless to say, the width of the second end may be zero also. That is,if it is desired to cause a large amount of air to collide against thefuel gas so as to increase the stirring effect, the width of the secondend will be set as zero. However, in case the diffusion of the fuel gashas developed already in the vicinity of the second end, if the air flowis caused to collide directly thereto, it will be difficult to diffusethe fuel gas to the outermost side of the main combustion channel. Insuch case, the width of the second end will be set as e.g. about 2 timesgreater than the width of the first supply opening.

With this construction, it is possible to increase/decrease the degreeof diffusion of the fuel gas in the radial direction of the maincombustion channel. Therefore, the equivalent ratio of the fuel-airmixture in the main combustion channel may be made uniform and low NOxgeneration can be realized while providing the gas supplying means asmeans with reduced pressure loss.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above is characterized infurther that a hollow tubular fuel supplying member having a porous wallportion is attached to the first supply opening.

That is to say, as proposed by the present construction, if the porousfuel supplying member is attached to the first supply opening for thefuel gas, the fuel gas will be gradually discharged through the poresformed in the wall portion of the fuel supplying member when the fuelgas moves in the radial direction of the main combustion channel, inother words, in the direction of the cross section of the channel of themain combustion channel. Therefore, the fuel gas may be diffuseduniformly over the entire main combustion channel.

In this, it is desired, however, that the porous material used in thisconstruction should have coarse pores as they are needed for preventingpressure loss in fuel supply. That is, the fuel supplying member used inthis construction should be such that it can restrain easy diffusion ofthe fuel gas when the fuel gas flows outwards in the radial direction.For instance, in case this fuel supplying member is disposed in the flowof the air, the member should have such pores as allow easy entry ofthis air flow into the interior of the fuel supplying member.

If such fuel supplying member is provided and also the first shieldingmember is provided on the upstream of this fuel supplying member, thefuel gas diffusion restraining effects of these two members will becombined to reliably allow the fuel gas to be diffused to the outer sideof the main combustion channel.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that said fluid distributor comprises a distributing memberwhich is provided in the main combustion channel and defines the firstsupply opening in its outer surface, and which forms therein an airinlet duct (an example of an oxygen-containing gas inlet duct) forguiding the air supplied from the supply line and the air supplyingmeans to the pilot combustion channel, and said distributing meansincludes, in said distributing member, a second supply opening fordischarging the fuel gas into the air inlet duct in a directionintersecting the flow direction of the air inside the air inlet duct, acommunication line for receiving the fuel gas discharged from the secondsupply opening and guiding it to the first supply opening, and areceiving opening for the communication line disposed at a positionopposing to the second supply opening with a predetermined distancerelative thereto in the discharging direction, with the receivingopening being open to the second supply opening.

That is to say, the distributing member is provided in the maincombustion channel and the wall portion of the air inlet duct formedinside this distributing member for introducing the air into the pilotcombustion channel defines the second supply opening for discharging thefuel gas into the air inlet duct and the wall portion of the air inletduct formed inside the distributing member defines the receiving openingopposing to the second supply opening via the air inlet duct, to whichopening the discharge of the fuel gas is directed. And, this receivingopening is connected via the communication line with the first supplyopening defined in the outer surface of the distributing member.

That is, the fuel gas supplied to the supply line inside thedistributing member is discharged from the second supply opening towardthe receiving opening of the air inlet duct.

And, in the gas supply area where the discharged fuel gas is present inthe air inlet duct inside the distributing member, a portion of the fuelgas transversing the air inlet duct is carried way by the air current ofthe air inlet duct to flow to the pilot combustion channel, while therest of the gas flows through the air current of the air inlet duct toreach the first supply opening via the receiving opening to be suppliedto the main combustion channel eventually.

More particularly, of the fuel gas discharged from the second supplyopening into the air inlet duct, the fuel gas portion introduced intothe communication line via the receiving opening will be guided to thefirst supply opening to be supplied to the main combustion channel.whereas, the other fuel gas portion not introduced into the receivingopening will be supplied via the air inlet duct to the pilot combustionchannel. And, the greater the amount and the greater the speed of thesupply of the fuel gas discharged from the second supply opening, thehigher the ratio of the portion of the discharged fuel gas introducedinto the receiving opening. As a result, the greater the supply amountof the fuel gas, the higher the distribution ratio of the fuel gas tothe side of the first supply opening, i.e. to the side of the maincombustion channel. Conversely, the smaller the amount of the supply ofthe fuel gas, the lower the distribution ratio of the fuel gas to theside of the main combustion channel.

Therefore, in the burner apparatus, the distributing means of the fluiddistributor may be realized with a simple construction.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that the distributing member preferably comprises a plate-likemember disposed within the main combustion channel with a plate facethereof being oriented along the flow direction of the oxygen-containinggas in the main combustion channel.

When the distributing member is provided within the main combustionchannel as described above, this sometimes results in disturbance in theair flow inside the main combustion channel. However, by constructingthis distributing member as a plate-like member having a plate facealigned in the air flow direction, such disturbance of the air in themain combustion channel can be minimized.

For accomplishing the above-noted object, a burner apparatus accordingto the present invention, includes a common channel formed at one end ofthe inner tube and the outer tube for supplying the oxygen-containinggas to the main combustion channel and the pilot combustion channel, acommon supply opening for discharging the fuel gas of the gas channel insaid common channel from the upstream side in the flow direction of theoxygen-containing gas of the pilot combustion channel to the upstreamside in the flow direction of the oxygen-containing gas of the maincombustion channel, and a common shielding member for adjusting theinflow amount of the oxygen-containing gas, for a common gas supply areawhich extends in a discharging direction of the fuel gas from theupstream side in the air flow direction of the common supply opening andfrom this common supply opening to the common channel.

Further, the burner apparatus of the present invention, in addition tothe burner apparatus construction described above, is characterized infurther that said first channel is used as the main combustion channeland said second channel is used as the pilot combustion channel.

That is to say, with the burner apparatus of the present invention, asin this construction, for example, the common channel is provided as achannel formed on the upstream side of the air flow of the inner tubeand inside the outer tube, and the common supply opening is provided forcausing the gas supplying means to discharge the fuel gas of the gaschannel in the above-described direction to the common channel.

Namely, the fuel gas supplied to the gas channel will be discharged fromthe common supply opening provided in the common channel disposed on theupstream side of the pilot combustion channel toward the common channeldisposed on the upstream side of the main combustion channel.

And, in the gas supply area where the discharged fuel gas is present inthe common channel, a portion of the fuel gas transversing the commonchannel is carried way by the air current of the air introduced in thepilot combustion channel to flow to the pilot combustion channel, whilethe rest of the gas flows through the air current introduced in thepilot combustion channel to reach the air introduced in the maincombustion channel to be supplied to the main combustion channeleventually.

Therefore, the greater the supply amount of the fuel gas to the gaschannel and the greater the discharging speed of the fuel gas from thecommon supply opening to the common channel, the higher the ratio of thefuel gas reaching the common channel on the upstream side of the maincombustion channel and flowing into the main combustion channel. As aresult, by increasing the supply amount of the fuel gas, it is possibleto increase the distribution ratio of the fuel gas to the maincombustion channel. Conversely, by decreasing the supply amount of thefuel gas, it is possible to decrease the distribution ratio of the fuelgas to the main combustion channel.

Further, with the burner apparatus having this construction, the commonshielding member is provided on the upstream side of the common supplyopening of the common channel, so that it is possible to restrain theinflow of the air from the upstream side at least to the common gassupply area where the fuel gas discharged in the common channel on theupstream of the pilot combustion channel is present, thereby toappropriately adjust the inflow amount of the air to the common gassupply area. Hence, in the common gas supply area, the ratio of the fuelgas reaching the upstream of the main combustion channel and introducedtherein may be adjusted appropriately, so that the distribution ratio ofthe fuel gas to the main combustion channel may be adjusted to suit theoperation condition of the burner apparatus.

Further, as this common shielding member restrains the inflow of the airfrom the upstream side of the air from into the gas area, it is possibleto increase the diameter of the common supply opening for reducing thedischarging speed of the fuel gas, eventually reducing the pressure lossof the fuel gas at the common supply opening.

Therefore, it is not necessary to adjust the supply amount of the fuelgas to the pilot combustion channel and the supply amount of the fuelgas to the main combustion channel independently of each other. Rather,the distributing means may be constructed such that only with adjustmentof the total supply amount of the fuel gas to the gas channel, thedistribution ratio of the fuel gas to the main combustion channel and tothe pilot combustion channel may be readily adjusted in accordance withe.g. combustion load variation. Moreover, the supply amount of the fuelgas to the pilot combustion channel may be increased in association withdecrease in the total supply amount of the fuel gas at the time of lowcombustion load, thereby to assure stable pilot combustion. At the sametime, the supply amount of the fuel gas to the main combustion channelmay be increased in association with increase in the total supply amountof the fuel gas at the time of the rated combustion load, so that thefuel gas may be distributed uniformly to the main combustion channel andthe pilot combustion channel to realize low NOx generation combustionwith lean fuel-air mixture. Accordingly, there is achieved a burnerapparatus which has a simple construction, but which achieves higherefficiency over wide combustion load range.

Further, in the burner apparatus of the present invention, of the outerfirst channel and the inner second channel, either combustion channelmay be used as the main combustion channel. However, if the outer firstchannel is used as the main combustion channel and the inner secondchannel is used as the pilot combustion channel, at the time of lowcombustion load when the distribution ratio of the fuel gas for thepilot combustion channel is increased, more fuel gas will be introducedto the inner pilot combustion channel for assuring stable pilotcombustion in the pilot combustion channel.

Also, the above-described burner apparatus of the present inventionwhich achieves low NOx generation and high efficiency over a widecombustion load range can be used by itself as a burner apparatus for anincinerator for example. However, this apparatus is particularly usefulas a burner apparatus for a gas turbine engine. Such gas turbine enginecan operate over a wide operational load range while maintaining low NOxreduction and high efficiency.

Further, with a co-generation system including the gas turbine enginehaving the fluid distributor and the burner apparatus of the inventionand a heat recovery device for recovering heat from exhaust gas, sincethe exhaust gas exhausted from the gas turbine engine has low NOxcontent, such device as a denitration device can be formed small oreliminated at all, so that cost reduction and size reduction of thesystem can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view in vertical section showing a first embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 2 is a front view in section of the burner apparatus shown in FIG.1,

FIG. 3 is a side view in vertical section showing principal portion ofthe fluid distributors shown in FIG. 1,

FIG. 4 is a perspective view showing the principal portion of the fluiddistributors shown in FIG. 3,

FIG. 5 is a side view in vertical section showing a second embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 6 is a side view in vertical section showing a third embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 7 is a front view in section of the burner apparatus shown in FIG.6,

FIG. 8 is a side view in vertical section showing a burner apparatusaccording to a modified mode of the third embodiment,

FIG. 9 is a side view in vertical section showing a fourth embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 10 is a front view in section of the burner apparatus shown in FIG.9,

FIG. 11 is a side view in vertical section showing principal portion ofthe fluid distributors shown in FIG. 10,

FIG. 12 is a front view in section showing the principal portion of thefluid distributors shown in FIG. 10,

FIG. 13 is a side view in vertical section showing a fifth embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 14 is a side view in vertical section showing a modified mode ofthe burner apparatus shown in FIG. 13,

FIG. 15 is a front view in section of the burner apparatus shown in FIG.14,

FIG. 16 is a side view in vertical section showing a sixth embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 17 is a front view in section of the burner apparatus shown in FIG.16,

FIG. 18 is a partial side view in vertical section showing a modifiedmode of the burner apparatus shown in FIG. 16,

FIG. 19 is a side view in vertical section showing a seventh embodimentof a burner apparatus having fluid distributors according to the presentinvention,

FIG. 20 is a partial side view in vertical section showing a modifiedmode of the burner apparatus shown in FIG. 19,

FIG. 21 is a side view in vertical section showing an eighth embodimentof a burner apparatus having fluid distributors according to the presentinvention,

FIG. 22 is a front view in section of the burner apparatus shown in FIG.21,

FIG. 23 is an enlarged side view of first supply openings of gassupplying means,

FIG. 24 is an enlarged plan view of the first supply openings of the gassupplying means,

FIG. 25 is a view showing variation of a fuel gas discharging amountrelative to a total fuel gas supply amount at each first supply opening,

FIG. 26 is an enlarged side view of first supply openings of gassupplying means relating to a modified mode of the eighth embodiment,

FIG. 27 is an enlarged side view of first supply openings of gassupplying means relating to a modified mode of the eighth embodiment,

FIG. 28 is an enlarged front view in section showing the first supplyopenings of the gas supplying means shown in FIG. 27,

FIG. 29 is an enlarged side view of first supply openings of gassupplying means relating to a modified mode of the eighth embodiment,

FIG. 30 is a side view in vertical section showing a ninth embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 31 is a front view in section of the burner apparatus shown in FIG.30,

FIG. 32 is an explanatory view showing a setting mode of a firstshielding member shown in FIG. 30,

FIG. 33 is a side view in vertical section showing a further embodimentof the burner apparatus shown in FIG. 30,

FIG. 34 is a perspective view showing a fuel supplying member providedin the burner apparatus,

FIG. 35 is a side view of a first supply opening of gas supplying meansrelating to a modified mode of the ninth embodiment,

FIG. 36 is a side view in vertical section showing a tenth embodiment ofa burner apparatus having fluid distributors according to the presentinvention,

FIG. 37 is a front view in section of the burner apparatus shown in FIG.36,

FIG. 38 is a side view in vertical section showing a burner apparatusrelating to a modified mode of the tenth embodiment,

FIG. 39 is a front view in section of the burner apparatus shown in FIG.38,

FIG. 40 is a side view in vertical section showing an eleventhembodiment of a burner apparatus having fluid distributors according tothe present invention,

FIG. 41 is a front view in section of the burner apparatus shown in FIG.40,

FIG. 42 is a side view in vertical section showing a burner apparatusrelating to a modified mode of the eleventh embodiment,

FIG. 43 is a side view in vertical section showing a twelfth embodimentof a burner apparatus having fluid distributors according to the presentinvention, and

FIG. 44 is a partial section showing a conventional burner apparatus asa comparison example.

BEST MODE OF EMBODYING THE INVENTION FIRST EMBODIMENT

A first embodiment of a burner apparatus relating to the presentinvention will be described below.

A burner apparatus for use in a gas turbine engine, an incinerator,etc., as shown in FIG. 1 and FIG. 2, includes a gas tube 1 defining agas channel A3, an inner tube 2 defining a second channel A2 as a pilotcombustion channel surrounding the gas tube 1, an outer tube 3 defininga first channel A1 as a main combustion channel surrounding the innertube 2, an air supplying means (an example of “oxygen-containing gassupplying means”) for supplying air A (an example of “oxygen-containinggas”) as a first fluid to the first channel A1 and the second channelA2, and a gas supplying means for supplying fuel gas G as a second fluidto the first channel A1 and the second channel A2. In operation, thefuel gas G and the combustion air A are supplied to the main combustionchannel and the pilot combustion channel to be mixed in the channels toprovide a fuel-air mixture, which is combusted in a combustion chamber15.

The gas tube 1, the inner tube 2 and the outer tube 3 are disposedcoaxially. That is, the first channel A1, the second channel A2 and thegas channel A3 are juxtaposed.

The air supplying means is a means for forcing the air A into the firstchannel A1 and the second channel A2 from one end thereof by means of anunillustrated compressor, blower, etc.

The gas supplying means is a means for supplying the fuel gas G from anunillustrated gas supply source storing the fuel gas G therein via anunillustrated duct to the gas channel A3 and for distributing the fuelgas G inside this gas channel A3 to the first channel A1 and to thesecond channel A2. That is to say, the means is provided for supplyingthe fuel gas G to the gas channel A3 and distributing means is providedfor distributing the fuel gas G inside this gas channel A3 to the firstchannel A1 and to the second channel A2.

The distributing means comprises a plurality of fluid distributors 4distributed in the peripheral direction across the three channels of thefirst channel A1, the second channel A2 and the gas channel A3 fordistributing the fuel gas G inside the gas channel A3 to the firstchannel A1 and to the second channel A2.

Each fluid distributor 4, as shown in FIG. 3 and FIG. 4, includes aplurality of first supply openings 5 for supplying the fuel gas G intothe first channel A1 and supply lines 6 for supplying the fuel gas G inthe gas channel A3 to the respective first supply openings 5independently of each other, each supply line 6 including distributingmeans for distributing the fuel gas G into the first channel A2 in sucha manner that the distribution ratio of the fuel gas G to the firstsupply openings 5 is increased in association with increase in thesupply amount of the fuel gas G from the gas channel A3 to the firstchannel A1 and the second channel A2, and conversely the distributionratio of the fuel gas to the first supply openings 5 is decreased inassociation with decrease in the total supply amount of the fuel gas G.

Referring to the distributing means, each supply line 6 includes anozzle 16 having a second supply opening 7 for discharging the fuel gasG into the second channel A2 from the gas channel A3 in a directionnormal to the direction of the air A inside this second channel A2, acommunication line 8 for receiving the discharged fuel gas G from thissecond supply opening 7 and guiding it to the first supply openings 5,and a receiving opening 9 for the communication line 8 formed at aposition opposing to the second supply opening 7 and spaced aparttherefrom with a predetermined distance, the receiving opening beingopen to the second supply opening 7.

The plurality of first supply openings 5 of each fluid distributor 4 areformed on an end face of plate-like member 10 which is disposed in thefirst channel A1 along the flow direction of the air A, with theopenings being open in a same direction and spaced apart from each otherwith a predetermined distance along the flow direction of the air A, andthe respective communication lines 8 of the supply lines 6 are formedinside the plate-like member 10.

The end face of the plate-like member 10 is disposed with such a posturethat the face extends away from the side of the second channel A2 on thedownstream side in the flow direction of the air A. That is to say, theplurality of first supply openings 5 of each fluid distributor 4 areopen in the same direction in the upstream direction of the flow of theair A and are distributed along the width direction (radial direction)of the first channel A1 which is the direction distant from the secondchannel A2.

Therefore, when this fluid distributing means is in operation, as thesupply amount of the fuel gas G inside the gas channel A3 is increased,the distribution ratio of the fuel gas G to the side of the first supplyopenings 5 will be increased, thereby to supply a greater amount of thefuel gas G to the first channel A1. And, as a plurality of the fluiddistributors 4 are distributed along the peripheral direction and thefirst supply openings 5 of each fluid distributor 4 are distributedalong the width direction of the first channel A1, the fuel gas G may besupplied in diffusion in the first channel A1 in the width direction andthe peripheral direction of the first channel A1.

Further, since the first supply openings 5 are formed in the end face ofthe plate-like member 10 opposing to the upstream side of the flow ofthe air A, the fuel gas G supplied from the first supply openings 5 intothe first channel A1 will be caused to collide against this end face bythe current of the air A, thereby to achieve uniform mixing in the firstchannel A1.

And, at a portion of the first channel A1 downstream of the fluiddistributors 4, there is provided a first swirler 11 for providing aswirling force to the fuel-air mixture of the air A and the fuel gas G.

At an intermediate portion of the second channel A2 in the flowdirection, there is provided a second swirler 12 for providing aswirling force to the fuel-air mixture of the air A and the fuel gas Gintroduced into this second channel A2.

With these swirlers 11, 12, it is possible to improve the flamestability of the main combustion by the flame of the pilot combustion.Namely, when the fuel-air mixture mixed concurrently with theapplication of the swirling force from the second swirler 12 is ignitedby an unillustrated ignition device, this fuel-air mixture will beignited to provide a pilot combustion. And, as the flame of this pilotcombustion ignites the fuel-air mixture having flown through the firstchannel A1, the fuel-air mixture is combusted to provide a maincombustion.

Further, adjacent the downstream end of the inner tube 2, there isprovided an air stage ring 13 for combing and mixing a portion of thefuel-air mixture having flown through the first channel A1 with thefuel-air mixture having flown through the second channel A2.

Reference mark S in the drawing denotes struts distributed along theperipheral direction for supporting the inner tube 2 to the outer tube3.

Further, the nozzle 16 is a tubular member surrounding a radial portionof a second gas supply area in the second channel A2 where the fuel gasG is discharged from the second supply opening 7 of the supply line 6 tothe receiving opening 9. And, this nozzle functions as a secondshielding member for restraining inflow of the air A from the upstreamside of the flow of the air A into the second gas supply area, therebyappropriately adjusting the inflow amount of the air A.

That is to say, in the second channel A2, between the end of the nozzle16 and the receiving opening 9, there is formed a slit-like gap wherethe fuel gas G discharged into the second channel A2 is exposed to theflow of the air A. Then, by appropriately adjusting the width of thisslit-like gap by adjusting the height of the nozzle, the ratio of thefuel gas G flowing through the air A introduced into this slit-like gapto reach and enter the receiving opening 9 can be adjustedappropriately, so that the distribution ratio of the fuel gas to thefirst channel A1 may be adjusted to suit the operation condition of theburner apparatus.

Therefore, the distribution ratio of the fuel gas G to the first channelA1 and to the second channel A2 may be readily adjusted in associationwith e.g. variation of the combustion load.

Further, as the nozzle 16 restrains the inflow of the air A into thesecond gas supply area where the fuel gas G of the second channel A2 isdischarged, by increasing the diameter of the supply line 6 to reducethe discharging speed of the fuel gas G, pressure loss of the fuel gasat the gas supplying means can be reduced advantageously.

Also, as the nozzle 16, instead of the cylindrical member, a tubularmember of any shape such as an oval or oblong tubular shape or of asemicircular, semi-oval, triangular or rectangular shape may be usedalso.

Further, instead of this nozzle 16, it is possible to employ also, as amember extending over at least a portion of the upstream side of theflow of the air A of the second gas supply area, a plate-like memberwhich extends from the gas tube 1 on the upstream side of the flow ofthe air A of the second supply opening 7 toward the inner tube 2 andwhich has a plate face extending normal to the axial direction which isthe flow direction of the air A, or a plate-like member having a plateface inclined relative to the direction normal to the flow of the air A,or a curved or bent plate-like member in the form of a split tubularmember slip along the direction of the tube axis, having a cross sectionextending toward the inner tube 2 in the form of an arc, an oval arc,u-shaped or v-shaped surrounding at least the upstream side of thesecond supply opening 7.

Also, when such plate-like member is provided, it is also possible todefine a plurality of openings in this plate-like member for adjustingthe inflow amount or the distribution of the air A as the inflowcondition of the air A into the gas area. Further, the shape of each ofthese openings may be circular, semi-circular, oval, semi-oval,slit-like, or other polygonal shape. And, this shape may be determinedwith consideration of the cost and performance, etc.

Further, in the foregoing, the discharging direction of the fuel gas Gfrom the second supply opening 7 is set so that the fuel gas G isdischarged from the gas channel A3 in the direction normal to the flowdirection of the air A inside this second channel A2. However, thisdischarging direction is not particularly limited in the presentinvention. Preferably, the second supply opening 7 is constructed sothat the fuel gas G may be discharged into the second channel A2 withina range from a direction inclined by 20° toward the receiving opening 9relative to the flow direction of the air A inside the second channel A2to a direction inclined by 20° toward the receiving opening 9 relativeto the opposite direction to the flow of the air A.

SECOND EMBODIMENT

A second embodiment in which the fluid distributor 4 is different fromthe above-described embodiment will be described next.

In the case of the burner apparatus of the first embodiment, the firstsupply openings 5 are formed in the end face of the plate-like member 10opposing to the upstream side of the flow of the air A, so as to improvethe uniform mixing of the fuel gas G in the first channel A1.Alternatively, instead of disposing the end face defining the firstsupply openings 5 of the plate-like member 10 with the posture of theface departing from the second channel A2 on the downstream side of theflow direction of the air A, a construction shown in FIG. 5 is alsopossible. In this case, on the contrary to the first embodiment, thefirst supply openings 5 are formed in an end face of the plate-likemember 10 opposing to the flow of the air A, with the end face beingoriented with a posture of the face approaching the second channel A2 onthe downstream side of the flow direction of the air A.

With this construction too, the object of the invention may be achievedsuch that the fuel gas G is supplied with a predetermined distributionratio between the first channel A1 and the second channel A2 with thesupply amount adjustment of the fuel gas G inside the gas channel A3.

THIRD EMBODIMENT

Next, a third embodiment different from the first and second embodimentswill be described with reference to FIGS. 6 through 8.

A burner apparatus shown in FIG. 6 and FIG. 7 includes, in addition tothe burner apparatus construction of the first embodiment shown in FIG.1 and FIG. 2, five mixing promoting members 36 against which the fuelgas G discharged from the first supply openings 5 of the fluiddistributors 4 is caused to collide in the direction away from the innertube 2, so that the collided gas G is diffused in the first channel A1as the main combustion channel. Further, these mixing promoting members36 are ring-like members disposed in distribution along the peripheraldirection of the first channel A1 and having plate faces along thedischarging direction of the fuel gas G from the plurality of firstsupply openings 5 which are distributed in the peripheral direction andequidistantly spaced apart from the inner tube 2.

With provision of such mixing promoting members 36, it is possible tocause the fuel gas G discharged from the first supply openings 5 tocollide against these mixing promoting members 36 to be diffusedthereby, so that the fuel gas G may be supplied uniformly relative tothe air a in the first channel A1.

Also, as the mixing promoting members 36 are ring-like members disposedalong the peripheral direction of the first channel A1, by causing thefuel gas G discharged from the plurality of first supply openings 5provided in the peripheral direction to collide the plate faces of thesering-like mixing promoting members 36, the fuel gas G may be diffused atleast in the peripheral direction of the first channel A1.

And, by providing the mixing promoting members 36 in the first channelA1, the fuel gas G may be supplied uniformly into the first channel A1,without significant pressure loss. And, with the reduction of pressureloss at the first supply opening 5, the distributing means allows thefuel gas G discharged from the second supply opening 7 into the secondchannel A2 to be received efficiently into the receiving openings 7.

Further, as shown in FIG. 8, the ring-like mixing promoting members 36can be provided also in the burner apparatus of FIG. 5 relating to thesecond embodiment.

Incidentally, the ring-like mixing promoting members 36 may be providedintermittently for the plurality of first supply openings 5. That is,the mixing promoting member 36 may be provided as a ring-like memberhaving a plate face only in the vicinity of the first supply openings 5.Further, e.g. the shape of each plate face may be a shape designed inconsideration to the diffusion condition of the fuel gas. Further, theshape need not be the same in the peripheral direction.

FOURTH EMBODIMENT

Next, a fourth embodiment in which the fluid distributor 4 is differentfrom those of the foregoing embodiments will be described.

As shown in FIGS. 9 through 12, in this case, the first supply openings5 are not formed in an end face of the plate-like member 10. Rather, inone of the two plate faces, there are formed a plurality of first supplyopenings 5 for discharging the fuel gas G in the direction normal to theplate face, with the openings being distributed in the width directionof the first channel A1 and the flow direction of the air A; and in theother plate face too at its each position opposing to each said firstsupply opening 5 in the plate thickness direction, there is formed afirst supply opening 5 for discharging the fuel gas G in the directionnormal to the plate face. And, in the plate-like member 10, there areformed a plurality of supply lines 6 (communication lines 8) for guidingthe fuel gas G from the gas channel A3 to the plurality of first supplyopenings 5 independently of each other, with one supply line 6 beingprovided for each two first supply openings 5 opposed to each otherequidistantly from the second channel A2.

And, a plurality of the plate-like members 10 are arranged with therespective plate faces thereof being aligned with the spiral directionof the first channel A1, and of the fins 11 a of the swirler 11 forproviding a swirling force to the air A supplied to the first channelA1, those disposed alternately in the peripheral direction areconstituted from the plate-like members 10.

FIFTH EMBODIMENT

A fifth embodiment of the burner apparatus of the invention will bedescribed next with reference to FIGS. 13 through 15.

With the burner apparatus shown in FIG. 13, as the gas supplying means,instead of the fluid distributors 4 of the foregoing embodiments, of twogas channels A3, one gas channel A3 is communicated with the secondsupply opening 7 for supplying the fuel gas G to the second channel A2and the other is communicated via the supply line 6 with the firstsupply opening 5 for supplying the fuel gas G to the first channel A1.And, with this construction too, by the adjustment of the supply amountof the fuel gas G to the two gas channels A3, the fuel gas G may besupplied by a predetermined distribution ratio to the first channel A1as the main combustion channel and to the second channel A2 as the pilotcombustion channel.

And, in this embodiment, the first supply opening 5 is formed so as todischarge the fuel gas G to more upstream side in the flow direction Xof the air A than the direction normal to the flow direction X of theair A in the first channel A1. To this end, in the embodiment, the endof the supply line 6 is bent in a predetermined direction.

More particularly, in the present embodiment, the first supply opening 5with 180 degrees in opposition to the flow direction of the air A. Inthis case, it is possible to maximize the relative speed between the airA and the fuel gas G, thus enhancing the mixing degree of the fuel gas.

Incidentally, the opening direction of the first supply opening 5 neednot be opposite to the air A as described above. Preferably, thedirection should be set within a range of 80 degrees from the upstreamside relative to the flow direction X of the air A. In this case too,the relative speed between the air A and the fuel gas G may be setrelatively large, whereby fuel-gas mixture having good mixing degree maybe obtained.

As described above, with the burner apparatus of the present invention,it is not necessary to provide a plurality of small-diameter dischargeopenings in the radial direction Y of the first channel A1 for onesupply line 6. That is, it is not necessary to increase the supplyingpressure of the gas supplying means. As a result, since the fuel gas Gmay be discharged with such a pressure just enough to overcome thepressure of the air A, the discharging pressure or the discharging speedof the fuel gas G may be reduced, whereby pressure loss during thesupply of the fuel gas G may be reduced advantageously.

A combustion evaluation test was conducted with using the burnerapparatus shown in FIG. 13, with a test pressure of 119 kPa (abs) (1.21kgf/cm² (abs)). In this test, in order to confirm the pressure-lossreduction effect relating to the supply of the fuel gas G to the firstchannel A1 and the NOx reduction effect due to the uniform mixing in thefirst channel A1, the burner apparatus shown in FIG. 13 was employed sothat the first supply openings 5 and the gas channel A3 were directlycoupled with each other so that the fuel gas G was supplied to the firstsupply openings 5 and the supply of the fuel gas G to the second channelA2 was effected separately. Incidentally, the first supply opening 5 hadan inner diameter of 2.6 mm ø and the fuel gas G was supplied from eightfirst supply openings 5 to the first channel A1.

The result showed a NOx generation amount less than 10 ppm as measuredwith 0% oxide and the combustion efficiency of 99% or more and themaximum pressure loss in the fuel supply to the first channel A1 being56 kPa (0.57 kgf/cm²).

In the case of a burner apparatus shown in FIG. 44 as a comparisonexample, in this case too, as eight tube forming members 41 are providedalong the peripheral direction of the first channel A1, there are 24 ofdischarge openings 30 in total. The inner diameter of each dischargeopening is 0.7 mm ø.

In the case of the burner apparatus of FIG. 44, the NOx generationamount was less than 13 ppm as measured with 0% oxide and its combustionefficiency was more than 99%. However, the maximum pressure loss in thefuel supply to the first channel A1 was 250 kPa (2.55 kg/cm²), which issignificantly greater than the burner apparatus of FIG. 13. This showsthat the burner apparatus according to the present invention achievesthe pressure-loss reduction effect while maintaining uniform mixing.

The conditions employed in the above-described combustion evaluationtest were 350° C. for the temperature of air A, 0.35 equivalent ratio ofthe fuel gas G relative to the air A, 2.6 m³/h (Normal) for the fuelsupply amount to the second channel A2, 23.6 m³/h (Normal) for the fuelsupply amount to the first channel A1, and 1000° C. for TIT (averagetemperature at the exit of combustor (entrance to the turbine)).

Next, there will be described a case using such gas supplying means incombination with the fluid distributor.

Namely, like the foregoing embodiment, a burner apparatus shown in FIG.14 is constructed such that the fluid distributor 4 as the gas supplyingmeans is adapted for receiving, from the second channel A2, at least aportion of the fuel gas G supplied from the second supply opening to thesecond channel A2 and then supplying it to the first channel A1.

That is to say, like the foregoing embodiment, the single gas channel A3is communicated only with the second supply opening 7. And, this secondsupply opening 7 is open into the second channel A2. The dischargingdirection of the fuel gas G from the second supply opening 7 is directedsubstantially normal to the flow direction of the air A.

And, at a position opposed to the second supply opening 7, the innertube 2 defines the receiving opening 9 communicated with the firstsupply opening 5 provided in the first channel A1. For both the secondsupply opening 7 and the first supply opening 5, eight of them aredisposed in distribution along the peripheral direction Z of the burnerapparatus. Further, the position of the first supply opening 5 in theradial direction Y of the first channel A1 corresponds to the center ofthe width of the first channel A1.

Therefore, although this construction is very simple, it is possible toappropriate set the pilot combustion condition in the second channel A2and the main combustion condition in the first channel A1.

As shown in FIG. 15, in this embodiment, 8 (eight) supply lines 6 areequidistantly disposed along the peripheral direction Z of the firstchannel A1. In operation, the fuel gas G discharged from each supplyline 6 is caused to collide the air A to be dispersed to the outer sidefrom first supply opening 5 as the center. As a result, the fuel gas Gmay be dispersed and mixed substantially over the entire area of thefirst channel A1, thereby to achieve substantially constant equivalentratio of the fuel-air mixture.

SIXTH EMBODIMENT

Next, a further sixth embodiment relating to the fifth embodiment willbe described with reference to FIGS. 16-18.

The burner apparatus shown in FIGS. 16 and 17, in addition to the burnerapparatus construction relating to the fifth embodiment shown in FIGS.14 and 15, includes a mixing promoting member 36 against which the fuelgas G discharged from the first supply opening 5 of the fluiddistributor 4 collides in the direction opposite to the flow directionof the air A in the first channel A1 to be dispersed in the firstchannel A1 functioning as the main combustion channel. This mixingpromoting member 36 is a ring-like member extending along the peripheraldirection of the first channel A1 and having a plate face oriented alongthe discharging direction of the fuel gas G from the plurality of firstsupply openings 5.

With provision of such mixing promoting member 36, it is possible tocause the fuel gas G discharged from the first supply openings 5 tocollide this mixing promoting member 36 to be dispersed at least in theperipheral direction of the first channel A1, thereby to supply the fuelgas G uniformly to the air a in the first channel A1.

And, by providing the mixing promoting member 36 in the first channelA1, it is possible to supply the fuel gas G uniformly to the firstchannel, without involving significant pressure loss. The distributingmeans may be constructed such that the fuel gas G discharged from thesecond supply opening 7 into the second channel A2 may be effectivelyreceived by the receiving opening 9 thanks to the reduced pressure lossat the first supply openings 5.

Further, as shown in FIG. 18, if the opening direction of the firstsupply opening 5 is set with an inclination relative to the oppositedirection to the flow direction X of the air A, the ring-like mixingpromoting member 36 may be provided with a plate face oriented towardthe first supply opening 5 so as to allow the fuel gas G discharged fromthis first supply opening 5 to collide against the face.

Moreover, such mixing promoting member 36, in addition to the burnerapparatus having the fluid distributor 4, may also be provided for thefirst supply opening 5 or the second supply opening 7 of the burnerapparatus shown in FIG. 13.

SEVENTH EMBODIMENT

Next, a further embodiment of the mixing promoting member will bedescribed with reference to FIGS. 19-20.

In the case of the burner apparatus shown in FIG. 19, the openingdirection of the first supply opening 5 for supplying the fuel gas tothe first channel A1 is set to a direction away from the inner tube 2extending normal to the flow direction of the air A of the first channelA1 toward the outer tube 3.

And, with this burner apparatus, it is possible to employ, as the mixingpromoting member 36, a ring-like member which has a plate face extendingaway from the first supply opening 5 toward the outer tube 3 and whichextends along the peripheral direction of the first channel A1. So that,the it becomes possible to cause the fuel gas G discharged from thefirst supply opening 5 to collide against the mixing promoting member36, thus being dispersed at least along the peripheral direction of thefirst channel A1.

Further, as shown in FIG. 20, it is also possible to employ a mixingpromoting member 36 constructed as a ring-like member having a plateface for collision with the fuel gas G oriented on the upstream side inthe flow direction of the air A in the first channel A1. So that, thefuel gas G having collided against the mixing promoting member 36 willbe directed in the direction opposite to the flow direction of the air Awhile being dispersed in the peripheral direction of the first channelA1, thus being dispersed over the entire first channel A1. As a result,the fuel gas G may be even more uniformly supplied to the first channelA1.

EIGHTH EMBODIMENT

An eighth embodiment of the burner apparatus relating to the presentinvention will be described next with reference to FIGS. 21-29.

The burner apparatus shown in FIGS. 21-24 is constructed, like theforegoing embodiment, such that its fluid distributor 4 is adapted forreceiving, from the second channel A2, at least a portion of the fuelgas G supplied from the second supply opening 7 into the second channelA1 and then supplying it to the first channel A1.

That is, each fluid distributor 4 includes five first supply openings 5a, 5 b, 5 c, 5 d, 5 e for supplying fuel gas into the first channel A1,with the openings being distributed in the width direction (thedirection away from the second channel A2) of the first channel A1. Foreach of these five first supply openings 5, there is independentlyprovided a supply line 6 for supplying the fuel gas G inside the gaschannel A3, so that the fuel gas may be supplied in distribution intothe second channel A2. And, the respective supply lines 6 areconstructed such that the distribution ratio of the fuel gas to besupplied to the first supply openings 5 is increased in association withincrease in the total supply amount of the fuel gas G from the gaschannel A3 to the first channel A1 and to the second channel A2 andconversely the distribution ratio of the fuel gas to the second channelA2 is increased in association with decrease in the total supply amountof the fuel gas G.

That is to say, each supply line 6 includes a nozzle 16 having a secondsupply opening 7 for discharging the fuel gas G in the second channel A2from the gas channel A3 in the direction normal to the flow direction ofthe air A in this second channel A2 and a communication line 8 forreceiving the fuel gas G discharged from the second supply opening 7 andguiding it to the first supply opening 5, and the communication line 8includes a receiving opening 9 at a position opposed to and spaced apartby a predetermined distance from the discharging direction of the secondsupply opening 7, with the receiving opening being open toward thesecond supply opening 7.

Further, each fluid distributor 4 is constructed such that dischargingresistance of the fuel gas G at each of the first supply openings 5 a, 5b, 5 c, 5 d, 5 e due to the passage of the air A is increased as beingdistant from the second channel A2.

That is, as shown in FIGS. 23 and 24, the opening direction of the firstsupply opening 5 a closest, in the first channel A1, to the secondchannel A2 is set normal to the flow direction of the air A. Then, theopening directions of the subsequent first supply openings 5 areoriented toward the upstream side in the flow direction of the air A, asbeing away from the second channel A2, with the opening direction of thefirst supply opening 5 e farthest from the second channel A2 being seton the upstream side in the flow direction of the air A. Namely, in eachfluid distributor 4, the discharging angles of the fuel gas from therespective first supply openings 5 relative to the upstream side of theflow direction of the air A in the first channel A1 are decreasedgradually as the openings are away from the second channel A2, so thatdischarging resistance of the fuel gas G due to the passage of the air Aat each first supply opening 5 is increased as being away from thesecond channel A2.

Therefore, as shown in FIG. 25, in the case of a low-load combustionwith reduced gas supply amount from the gas channel A3, of therespective first supply openings 5, the first supply openings 5 d, 5 edisposed away from the second channel A2, cannot discharge the fuel gasG due to the greater discharging resistance of the fuel gas G and onlythe other first supply openings 5 a, 5 b, 5 c disposed closer to thesecond channel A2 and hence providing reduced resistance against thedischarge of the fuel gas G can discharge the fuel gas G to the firstchannel A1. As a result, the fuel gas G passing in the first channel A1for the main combustion may be ignited and combusted appropriately, in asimilar manner to the pilot combustion taking place at the downstreamend of the second channel A2.

Next, a modified embodiment of the fluid distributor 4, different fromthe sixth embodiment, will be described.

In the case of the fluid distributor 4 shown in FIG. 26, the dischargingdirections of the fuel gas G from five first supply openings 5 a, 5 b, 5c, 5 d and 5 e are set to the upstream direction in the flow directionof the air A in the first channel A1. In addition, the opening areas ofthe respective first supply openings 5 a, 5 b, 5 c, 5 d and 5 e are setto increase gradually as being away from the second channel A2.

Of these first supply openings 5, discharging resistance of the fuel gasG developed in association with the discharging of the fuel gas in thedirection opposed to the flow direction of the air A is graduallyincreased from the supply opening 5 a disposed adjacent the secondchannel A2 to the first supply opening 5 e disposed away from the secondchannel A2. Hence, like the sixth embodiment described above, it ispossible to improve the combustion stability at the time of low-loadcombustion.

Next, another modified embodiment of the fluid distributor 4, differentfrom the sixth embodiment, will be described.

In the case of the fluid distributor 4 shown in FIG. 27, five firstsupply openings 5 a, 5 b, 5 c, 5 d, 5 e are formed in a plate-likemember 10 disposed along the flow direction of the air A in the firstchannel A1. The openings are open in outer faces of the plate-likemember and spaced apart with a predetermined appropriate distance alongthe flow direction of the air A and the respective communication lines 8are formed within the plate-like member 10.

Further, in these first supply openings 5, referring first from thecloser side to the first channel, the first supply opening 5 a isdefined in a side face 10 a of the plate-like member 10 which extendscloser to the second channel A2 on the downstream side of the flowdirection of the air A. As this side face 10 a faces the downstream sidein the flow direction of the air A, the fuel gas G from this supplyopening 5 a is sucked by the current of the air A toward the firstchannel A1, thereby to develop a negative discharging resistance for thefuel gas G.

Also, the next first supply opening 5 b, as shown in FIG. 28, is formedin a further side face 10 b of the plate-like member 10 oriented alongthe flow direction of the air A. So, the discharging resistance of thefuel gas G at this opening is provided only from the static pressure ofthe air A, thus providing a greater discharging resistance of the fuelgas G than the first supply opening 5 a.

The next first supply opening 5 c is defined in a side face 10 c of theplate-like member 10 oriented away from the second channel A2 on thedownstream side of the flow direction of the air A. Hence, due to theshape of the communication line 8 adjacent this first supply opening 5c, the fuel gas g will be discharged in the direction normal to the flowdirection of the air A. As the side face 10 c faces the upstream side inthe flow direction of the air A, this first supply opening 5 c providesa greater discharging resistance of the fuel gas G.

The other first supply openings 5 d, 5 e are formed in the same sideface 10 c as the above-described first supply opening 5 c. However, dueto the configurations of the communication lines 8 thereof, theseopenings discharge the fuel gas G in the direction opposed to the flowdirection of the air A. So, that the discharging resistances of the fuelgas C at these respective supply openings 5 may increase as being awayfrom the second channel A2. In this way, like the foregoing embodiment,it is possible to improve the combustion stability at the time oflow-load combustion.

Next, a still further modified embodiment of the fluid distributor 4,different from the sixth embodiment, will be described.

In the case of the fluid distributor 4 shown in FIG. 29, the distributorcomprises a tubular member having a communication line 8 for receiving,in the first channel A1, the fuel gas from the gas channel A3, thetubular member defining, it its lateral face, first supply openings 5 a,5 b, 5 c, 5 d, 5 e. And, in order to allow the discharging resistance ofthe fuel gas G at the respective first supply openings 5 as being awayfrom the second channel A2, the opening directions of the first supplyopenings 5 a, 5 b closer to the second channel A2 in the first channelA1 are set to be normal to the flow direction of the air A, whereas theopening directions of the other first supply openings 5 c, 5 d, 5 edistant from the second channel A2 are set to be the upstream of theflow direction of the air A.

In the case of the burner apparatus relating to this embodiment as well,instead of using the fluid distributors 4 as the gas supplying means, itis possible to effect the supply of the fuel gas from the gas channel A3to the first supply openings and the second supply openingsindependently of each other, so that through adjustment of the supplyamounts of the fuel gas to the respective supply openings, the fuel gasG may be supplied by a predetermined distribution ratio to the firstchannel A1 and the main combustion channel and to the second channel A2as the pilot combustion channel.

NINTH EMBODIMENT

A ninth embodiment of a burner apparatus relating to the presentinvention will be described with reference to FIGS. 30-35.

The burner apparatus shown in FIGS. 30-32, like the foregoingembodiments, is constructed such that the fluid distributor 4 mayreceive, from the second supply opening 7, at least a portion of thefuel gas G supplied from this second supply opening 7 to the secondchannel A2 and then supply it into the first channel A1.

That is, a single gas channel A3 is communicated only with the secondsupply opening 7. This second supply opening 7 is open into the secondchannel A2. Further, the discharging direction of the fuel gas G fromthe second supply opening 7 is set to be substantially normal to theflow direction of the air A.

And, at a position opposed to the second supply opening 7, the innertube 2 defines a receiving opening 9 communicated with the first supplyopening 5 provided in the first channel A1. Both the second supplyopenings 7 and the first supply openings 5 are distributed along theperipheral direction Z of the burner apparatus.

Hence, with such simple construction, it is possible to appropriatelyset the pilot combustion condition in the second channel A2 and the maincombustion condition in the first channel A1.

Along the flow direction of the air A, on the upstream side of the firstsupply opening 5, there is provided a first shielding member 29 forblocking the flow of the air A. By blocking the flow of the air A, thedispersion degree of the fuel gas G to the first channel A1 is improved.More particularly, in FIG. 30, the fuel gas G discharged from the firstsupply opening 5 into the first channel A1 flows first outwards alongthe radial direction Y of the first channel A1. However, if the air Acollides sideways this fuel gas G, the fuel gas G will be deflectedtoward the downstream of the first channel A1. And, if the dischargingspeed of the fuel gas G is low, there is risk that the gas will not bedispersed sufficiently to the outer periphery of the first channel A1.For this reason, the first shielding member 29 is provided on theupstream side of the first supply opening 5.

In this embodiment, as shown in FIGS. 30 and 31, as the first shieldingmember 29, there is employed a plate-like member which extends along theradial direction Y of the first channel A1.

This first shielding member 29, as shown in FIG. 32 for example, isconstructed such that a ratio: c/e, between a distance (c) from theopening center of the first supply opening 5 defined along the axialdirection X and the opening width (e) of the first supply opening 5 isgreater than or equal to 0.5 and smaller than or equal to 1.5.

Namely, if c/e is 0.5, the first supply opening 5 contacts the firstshielding member 29. Whereas, if c/3 is 1.5, the distance between thefirst shielding member 29 and the edge of the first supply opening 5 isequal to the opening width (e).

By setting the distance between the first supply opening 5 and the firstshied member 29 in the manner described above, it is possible toreliably prevent direct collision between the fuel gas G discharged fromthe first supply opening 5 an the air A, thereby to prevent the fuel gasG from being carried away by the air A unnecessarily to the downstreamside. Hence, the fuel gas G may be dispersed reliably to the outermostside in the first channel A1 and the equivalent ratio between the fuelgas G and the air A in the first channel A1 may be maintained constantfor realizing low NOx combustion.

The shape of the first shielding member 29 in its longitudinal directionmay be as shown in FIG. 32, for example.

Of the opposed ends of the first shielding member 29, one end adjacentthe first supply opening 5 is provided as a first end 30 and the otherend away from the first supply opening 5 is provided as a second end 31.The first end 30 has a width (a) along the peripheral direction Zrelative to the axial direction X and at the same time, the second end31 has a width (b) along the peripheral direction Z. Then, the firstshielding member 29 is constructed such that for the width (d) of thefirst supply opening 5 along the peripheral direction Z, the ratio: a/d,between the width (a) and the width (d) may be from 1 and 3 and theratio: b/d between the width (b) and the width (d) may be from 0 and 2,respectively.

In this way, by setting the width (a) of the first end 30 a along theperipheral direction Z of the first channel A1 as 1 to 3 times greaterthan the width (d) of the first supply opening 5 in the same directionand setting the width (a) of the first end 30 greater than the width (d)of the first supply opening 5, direction collision between the fuel gasdischarged from the first supply opening 5 an the air A may be avoided.With this, of the velocity components of the discharged gas G, thevelocity component in the radial direction Y may be maintained wellespecially, thereby to further improve the uniform mixing effect of thefuel gas G in the radial direction Y.

On the other hand, the width (b) of the second end 31 along theperipheral direction Z is set to be greater than or equal to 0 andsmaller than or equal to 2 times of the width (d) of the first supplyopening 5 in the same direction. The fuel gas G discharged from thefirst supply opening 5 will flow to the outer side in the radialdirection Y with some degree of dispersion. However, depending on thedischarging speed of the fuel gas G or other various conditions such asthe dimension of the first channel A1 in the radial direction Y, therewill occur differences in the dispersion condition of the fuel gas Greaching the vicinity of the second end 31. That is, byincreasing/decreasing the amount of air A to collide the fuel gas Gdepending on this degree of dispersion, the equivalent ratio of thefuel-air mixture is rendered constant.

More particularly, if it is desired to improve the uniform mixing effectof the fuel gas G in the vicinity of the second end 31, the width of thesecond end 31 is set to be zero so as to allow a great amount of air Ato collide the gas. Conversely, if the dispersion of the fuel gas G hasdeveloped already in the vicinity of the second end 31, so dispersion ofthe fuel gas to the outermost side in the first channel A1 is difficultwith direction collision with the air A, then, the width (b) of thesecond end 31 is set to be a greater value such as 2 times greater thanthe width (d) of the first supply opening 5.

With this construction, it is possible to increase/decrease the degreeof dispersion of the fuel gas G in the radial direction Y of the firstchannel A1. Therefore, the equivalent ration of the fuel-air mixture inthe first channel A1 may be rendered uniform. And, low NOx combustionmay be achieved while reducing the pressure of the gas supplying meansas the fluid distributor 4.

As described above, if the first shied member 29 is provided forpreventing the combustion air A from the upstream side along the axialdirection X of the first channel A1 from flowing into the first gassupply area 32 to which the fuel gas G is supplied, the fuel gas Gsupplied along the direction away from the inner tube 2 will be lessaffected by the flow of the air A, so that the gas may be readilydispersed to the outer side in the first channel A1. For this reason,the mixing between the fuel gas G and the air inside the first channelA1 may be rendered uniform, thus achieving low NOx combustion.

Further, adjacent the downstream side of the first supply opening 5,there is provided a projecting portion 38 projecting from the inner tube2 toward the first channel A1. With this, the straightness of the fuelgas discharged from the first supply opening 5 may be improved, so thatthe fuel gas G discharged from the first supply opening 5 into the firstchannel A1 may be even less affected by the current of air A.Consequently, the mixing between the fuel gas G and the air A can berendered even more uniform, thus further improving the NOx reductioneffect.

Also, if the fuel gas G can be dispersed easily to the outer side in thefirst channel A1 as described above, the discharging speed of the fuelgas G at the first supply opening 5 may be reduced and accordingly thesupplying pressure of the fuel gas G to the first channel A1 may bereduced for instance. As a result, the pressure loss of the fluiddistributor may be further reduced and such components as the gassupplying means may be formed compact.

Further, if the dispersion of the fuel gas G to the first channel A1 maytake place reliably as described above, the equivalent ratio between thefuel gas G and the air A may be rendered uniform at any given positionin the first channel A1. Consequently, such inconvenience as localoccurrence of high-temperature combustion can be avoided and the low NOxgeneration combustion becomes possible.

Next, an embodiment relating to specific dimensions of the firstshielding member 29 and the first supply opening 5 and the pressure lossexperienced in the supply of fuel gas G to the first channel A1 in thatembodiment will be explained.

Incidentally, in this test, in order to confirm the pressure-reductioneffect experienced in the supply of the fuel gas G to the first channelA1 as the effect of the first shielding member 29 and the low NOxgeneration effect due to the uniform mixing in the first channel A1, asshown in FIG. 33, in the burner apparatus of the present invention,instead of using the fluid distributor 4 of the foregoing embodiment, ofthe two gas channels A3, one of them is communicated with the secondsupply opening 7 for supplying the fuel gas to the second channel A2 andthe other is communicated via the supply line 6 with the first supplyopening 5 for supplying the fuel gas G to the first channel A1. And,thus modified gas apparatus was employed for the test.

Further, for the dimensions of the first shielding member 29 and thefirst supply opening 5, the width (a) of the first end 30 was set as 4.0mm, the width (b) of the second end 31 was set as 2.6 mm, and thedistance (c) between the first shielding member 29 and the center of thefirst supply opening 5 was set as 1.3 mm, and both the opening widths(d), (e) of the first supply opening 5 in the peripheral direction Z andin the axial direction X were set as 2.6 mm. That is, this is thecondition in which the first supply opening 5 contacts the firstshielding member 29.

On the other hand, the inner diameter of the first supply opening 5 wasset as 2.6 mm ø, and the second fuel gas G was supplied to the firstchannel A1 from eight first supply openings 5.

Then, by using this burner apparatus, a combustion evaluation test wasconducted with a testing pressure of 119 kPa (abs) (1.21 kgf/cm² (abs)).The results for the burner apparatus of FIG. 33 show the NOx generationamount less than 13 ppm with 0% oxygen conversion. The combustionefficiency was more than 99% and the maximum pressure loss in the supplyof fuel to the first channel A1 was 51 kPa (0.52 kgf/cm²).

The conditions employed in the above-described combustion evaluationtest were 350° C. for the temperature of air A, 0.35 equivalent ratio ofthe fuel gas G relative to the air A, 2.6 m³/h (Normal) for the fuelsupply amount to the second channel A2, 23.6 m³/h (Normal) for the fuelsupply amount to the first channel A1, and 1000° C. for TIT (averagetemperature at the exit of combustor (entrance to the turbine)).

The burner apparatus relating to this embodiment, as shown in FIG. 34,may include fuel supplying member 37 in the form of a hollow tube havinga porous wall portion 37 a, with the member 37 being attached to thefirst supply opening 5.

The fuel supplying member 37 is capable of supplying in distribution thefuel gas G through the pores formed in its wall portion 37 a. If theporous fuel supplying member 37 is attached to the first supply opening5 as proposed in this embodiment, the fuel gas G may be dischargedgradually from the pores formed in the wall portion 37 a of the fuelsupplying member 37 as the fuel gas G travels along the radial directionY of the first channel A1. So that, the fuel gas G may be distributeduniformly over the entire first channel A1.

However, it is preferred, for the purpose of preventing pressure lossduring fuel supply, that the porous member employed in this constructionhave coarse pores. That is to say, this fuel supplying member 37 shouldbe capable of restricting, to some extent, the dispersing tendency ofthe fuel gas G when the gas G travels to the outer side along the radialdirection Y. For instance, when this fuel supplying member 37 isdisposed in the middle of the current of the air A, the member shouldhave many pores which allow easy entrance of the air A into the fuelsupplying member 37.

As this fuel supplying member 37, it is possible to employ a sinteredbody of various metals, a mesh of metal or the like or an inorganicsintered body, etc.

Then, by providing such fuel supplying member 37 and also the firstshielding member 29 on the upstream side of this fuel supplying member37, the dispersing effects of these members for the fuel gas G may becombined, whereby the fuel gas G may be reliably dispersed to the outerside of the first channel A1.

Further, instead of the above-described plate-like member having theplate face oriented normal to the axial direction which is the flowdirection of the air A, as the first shielding member 29, it is possibleto employ a plate-like member having a plate face inclined relative tothe direction normal to the flow of the air A, or a curved or bentplate-like member in the form of a split tubular member slip along thedirection of the tube axis, having a cross section extending toward theinner tube 2 in the form of an arc, an oval arc, u-shaped or v-shapedsurrounding at least the upstream side of the first supply opening 5.Or, a tubular member surround the first supply opening 5 may be employedas well.

Also, if the tubular member is employed instead of the plate-like firstshielding member 29 as proposed above, it is also possible to employ atubular member 34 as shown in FIG. 35 which integrally includes a nozzleas a second shielding member for the second channel A2 and the tubularmember as the first shielding member for the first channel A1.

TENTH EMBODIMENT

A tenth embodiment of a burner apparatus relating to the presentinvention will be described next with reference to FIGS. 36-39.

The burner apparatus shown in FIGS. 36 and 37 is the so-calledcounter-flow type burner apparatus in which an air channel 50 isprovided for receiving supply of the air A in the opposite direction tothe flow direction of the fuel gas in the combustion chamber 15 and theair A is supplied from this air channel 50 to the first channel A1 andthe second channel A2.

Further, the fluid distributors 4 are provided in the first channel A1as the main combustion channel and each distributor 4 comprises adistributing member 51 which defines, in its outer face, a first supplyopening 5 and which defines, therein, a supply line 6 and an air inletduct 53 for guiding the air A supplied from the air channel 50 to thesecond channel A2 as the pilot combustion channel. The fluiddistributing means, includes, in said distributing member 51, a secondsupply opening 7 for discharging the fuel gas G into the air inlet duct53 in a direction intersecting the flow direction of the air A insidethe air inlet duct 53, a communication line 8 for receiving the fuel gasG discharged from the second supply opening 7 and guiding it to thefirst supply opening 5, and a receiving opening 9 for the communicationline 8 disposed at a position opposing to the second supply opening 7with a predetermined distance relative thereto in the dischargingdirection, with the receiving opening 9 being open to the second supplyopening 7.

Further, the distributing means 51 is a plate-like member disposedwithin the first channel A1, with its plate face oriented along the flowdirection of the air in the first channel A1. And, as shown in FIG. 39,as this plate-like distributing member 51, eight of them are disposed ateight positions equidistantly in the peripheral direction of the firstchannel A1, so that the air A supplied to the first channel may pass theouter face of the distributing means 51 substantially without anydisturbance.

With the above-described construction of the fluid distributor 4, in thegas supply area where the fuel gas G discharged from the second supplyopening 7 in the air inlet duct 53 within the distributing member 51 ispresent, a portion of the fuel gas G transversing the air inlet duct 53is carried way by the air current of the air inlet duct 53 to flow tothe second channel A2, while the rest of the gas flows through the aircurrent of the air inlet duct 53 to reach the first supply opening 5 viathe receiving opening 9 to be supplied to the first channel A1eventually. More particularly, of the fuel gas G discharged from thesecond supply opening 7 into the air inlet duct 53, the fuel gas portionintroduced into the communication line 8 via the receiving opening 9will be guided to the first supply opening 5 to be supplied to the firstchannel A1. whereas, the other fuel gas portion not introduced into thereceiving opening 9 will be supplied via the air inlet duct 53 to thesecond channel A2. And, the greater the amount and the greater the speedof the supply of the fuel gas G discharged from the second supplyopening 7, the higher the ratio of the portion of the discharged fuelgas G introduced into the receiving opening 9. As a result, the greaterthe supply amount of the fuel gas G, the higher the distribution ratioof the fuel gas G to the side of the first supply opening 5, i.e. to theside of the first channel A1. Conversely, the smaller the amount of thesupply of the fuel gas G, the lower the distribution ratio of the fuelgas to the side of the main combustion channel.

Further, as the first supply opening 5 is formed in the outer face ofthe distributing member 51, with the opening being open in the oppositedirection to the flow direction of the air A in the first channel A1,like the fifth embodiment described above, it is not necessary increasethe supply pressure of the gas supplying means and the fuel gas G may bedischarged with a pressure just enough to overcome the pressure of theair A. Accordingly, it is possible to set the discharging pressure orthe discharging speed of the fuel gas G low. As a result, thepressure-loss in the course of the supply of the fuel gas G may bereduced.

Also, instead of the plate-like shape described above, the plate-likemember 51 may be constructed in a form which does not significantlydisturb the air flow in the first channel A1. For instance, sit may beformed as a column-like member having a height along the radialdirection of the first channel. And, by providing this column-likemember with a cross-sectional shape such as a circular shape, an ovalshape having the major axis along the flow direction of the air A, atriangular shape having the apex on the upstream side in the flowdirection of the air A, or a streamline shape along the flow directionof the air A, it is possible to construct the distributing member 51 soas not to significantly disturb the flow of the air A.

This burner apparatus, conversely of the burner apparatuses describedhereinbefore, is an apparatus in which the first channel A1 is used asthe pilot combustion channel and the second channel is used as the maincombustion channel.

In operation, the air A supplied from the air supplying means issupplied first to the second channel A2 and a portion of this air Asupplied to the second channel A2 as the main combustion channel issupplied via the air inlet duct 53 formed in a distributing member 51(described later) to the first channel A1 as the pilot combustionchannel.

That is, the distributor member 51 is provided in the second channel A2as the main combustion channel. As shown in FIG. 39, this memberincludes, at the center thereof, an entrance opening of the air inletduct 53 open in the direction opposed to the flow direction of the air Aand the air inlet duct 53 is formed inside a portion of the memberextending radially from the center toward the inner tube 2, so that theair A introduced into the air inlet duct 53 is supplied to the firstchannel A1.

And, the distributing means includes, in the supply line 6 of thisdistributing member 51, a second supply opening 7 for discharging thefuel gas G into the air inlet duct 53 in a direction intersecting theflow direction of the air A inside the air inlet duct 53 and acommunication line 8 for receiving the fuel gas G discharged from thesecond supply opening 7 and guiding it to the first supply opening 5,and a receiving opening 9 for the communication line 8 disposed at aposition opposing to the second supply opening 7 with a predetermineddistance relative thereto in the discharging direction, with thereceiving opening 9 being open to the second supply opening 7. So that,the fuel gas may be supplied in distribution with a distribution ratioadjustment between the first channel A1 and the second channel A2.

ELEVENTH EMBODIMENT

Next, an eleventh embodiment of the burner apparatus relating to thepresent invention will be described with reference to FIGS. 40 through42.

With the burner apparatus shown in FIGS. 40 and 41, like the foregoingembodiments, the gas tube 1 includes a supply opening 46 (an example ofcommon supply opening). However, the upstream end of the inner tube 2 inthe flow direction of the air A is the terminal end of the supplyopening 46 in the flow direction of the air A. The air A supplied to acommon channel 47 formed on the upstream thereof is divided between thefirst channel 1 and the second channel 2 on the downstream side of thesupply opening 46. And, the fuel gas G is discharged from the supplyopening into the gas supply area extending in the width direction of thecommon channel 47.

That is, a portion of the fuel gas G supplied from the supply opening 46to the gas area is supplied to the second channel A2 as being carried bythe flow of the air A, while the rest of the gas will overcome the flowof the air A and reach the common channel 47 upstream of the firstchannel A1 via a plate-like member 55 to be described later and a gap 57formed at the upstream end of the first channel A1 in the flow directionof the air A, to be supplied eventually to the first channel A1.Accordingly, with a single fuel gas supplying means, it is possible tosupply the fuel gas G in distribution to the first channel A1 and to thesecond channel A2. Moreover, it is also possible to increase thedistribution ratio of the fuel gas to the second channel 2 inassociation with increase in the total supply amount of the fuel gas Gfrom the gas channel A1 to the first channel A1 and the second channelA2 and to conversely increase the distribution ratio of the fuel gas tothe second channel A2 in association with decrease in the total supplyamount of the fuel gas G.

Further, in the burner apparatus according to this embodiment, there isprovided the palate-like member 55 (an example of a common shieldingmember) which is disposed on the upstream side of the gas area in theflow direction of the air A and which has a plate face oriented normalto the flow direction of the air A. This plate-like member 55appropriately adjust the inflow amount of the air A by restrictingentrance of the air A into the gas area where the fuel gas G isdischarged.

With this plate-like member 55, like the above-described embodiments, itis possible to appropriately adjust the distribution ratio of the fuelgas G which flows into the first channel A1 and the second channel A2,whereby the distribution ratio of the fuel gas G may be adjusted to suitthe operating condition of the burner apparatus.

Further, in order to adjust the inflow condition of the air A into thegas area where the fuel gas G is discharged, the plate-like member 55may include a number of openings 55 a, so that the distribution ratio ofthe fuel gas G may be adjusted even more appropriately. The shape ofthis opening 55 a may be circular, semi-circular, oval or semi-oval,slit-like, or any polygonal shape. The specific shape may be determinedwith consideration of cost and performance, etc.

Further, in the burner apparatus of the present invention, instead ofthe plate-like member having a plate face extending normal to the axialdirection, i.e. the flow direction of the air A, as the plate-likemember 55, it is also possible to employ a plate-like member having aplate face inclined relative to the direction normal to the flow of theair A, or a curved or bent plate-like member in the form of a splittubular member slip along the direction of the tube axis, having a crosssection extending toward the outer tube 4 in the form of an arc, an ovalarc, u-shaped or v-shaped surrounding at least the upstream side of thesecond supply opening 7. And, as shown in FIG. 42, it is also possibleto provide, in the common channel 47 on the upstream of the secondchannel A2, s a tubular member 11 having the supply opening 46 of thegas tube 1 extending from the outer periphery to the portion immediatelybefore the upstream end of the inner tube 2.

TWELFTH EMBODIMENT

A twelfth embodiment of the burner apparatus according to the presentinvention will be described next with reference to FIG. 43

In the burner apparatus shown in FIG. 43, second supply openings 7 a, 7b, 7 c and first supply openings 5 a, 5 b, 5 c may be provided at aplurality of positions along the flow direction of the air A. Also, forthe respective second supply openings 7 a, 7 b, 7 c, e.g. tubularnozzles 16 a, 16 b, 16 c may be provided. Also, in this case, theheights (projecting amounts into the second channel A2) of therespective nozzles 16 a, 16 b, 16 c may be adjusted to become shorteralong the flow direction of the air A. So, that the distributionconditions of the fuel gas G from the respective second supply openings7 a, 7 b, 7 c to the first supply openings 5 a, 5 b, 5 c may be variedso as to supply the fuel gas G over a wide area in the first channel 1and the second channel 2.

In the embodiments described above, as a general example, air isemployed as the oxygen-containing gas for fuel combustion. Instead, asan oxygen-containing gas for fuel combustion other than the air, it isalso possible to employ e.g. an oxygen-enriched gas having a highercontent of oxygen than air.

The burner apparatus relating to the present invention may beconstructed as a straight-flow burner apparatus in which the flowdirection of the air supplied to the main and pilot combustion channelsagrees with the flow direction of the fuel gas in the combustion chamber15 or as a counter-flow burner apparatus in which the air flows in theouter side of the outer tube 3 in the opposite direction to the flowdirection of the fuel gas in the combustion chamber 15 to be supplied tothe respective combustion channels.

INDUSTRIAL APPLICABILITY

As described above, the burner apparatus and fluid distributor accordingto the present invention are useful as a fluid distributor and a burnerapparatus utilizing the distributor with which the adjustment of thesupply amounts of the fuel gas to the main combustion channel and thepilot combustion channel may be effected easily and also thedistribution ratio of the supply amount to the pilot combustion channelmay be increased in association with decrease in the supply amount. Inparticular, these are suitable for a gas turbine engine for electricitygeneration, a co-generation system including such gas turbine engine oras a burner apparatus for use in e.g. an incinerator.

What is claimed is:
 1. A burner apparatus comprising an inner tubedefining a second channel and an outer tube defining a first channelsurrounding the inner tube, oxygen-containing gas supplying means forsupplying oxygen-containing gas to the first channel and the secondchannel, and gas supplying means for supplying fuel gas to the firstchannel and the second channel, either the first channel or the secondchannel being used as a main combustion channel and the other being usedas a pilot combustion channel, the main combustion channel and the pilotcombustion channel receiving the supply of fuel gas for combusting it;wherein said gas supplying means includes a plurality of fluiddistributors arranged in dispersion in a peripheral direction of themain combustion channel and the pilot combustion channel, each fluiddistributor including a first supply opening for supplying the fuel gasinto the main combustion channel, a supply line for supplying the fuelgas present inside the gas channel to the first supply opening, anddistributing means incorporated in the supply line for distributing thefuel gas into the pilot combustion channel so that the distributionratio of the fuel gas to be supplied to the first supply opening isincreased in response to increase in a total supply amount of the fuelgas from the gas channel and conversely the distribution ratio of thefuel gas to be supplied to the first supply opening is decreased inresponse to decrease in the total supply amount.
 2. The burner apparatusaccording to claim 1, wherein the first channel is used as the maincombustion channel and the second channel is used as the pilotcombustion channel.
 3. The burner apparatus according to claim 1,wherein the distributing means includes, in the supply line, a secondsupply opening for discharging the fuel gas into the pilot combustionchannel in a direction normal to the flowing direction of theoxygen-containing gas inside the pilot combustion channel and acommunication line for receiving the fuel gas discharged from the secondsupply opening and guiding the gas into the first supply opening, and ata position opposed to the second supply opening and spaced apart by apredetermined distance in the discharging direction of the second supplyopening, there is provided a receiving opening of the communication lineas to be open toward the second supply opening.
 4. The burner apparatusaccording to claim 3, wherein at least one of the first supply openingand the second supply opening comprises a slit-like opening having alongitudinal direction along the peripheral direction of the maincombustion channel and the pilot combustion channel.
 5. The burnerapparatus according to claim 1, wherein said fluid distributor includesa plurality of said first supply openings distributed in the maincombustion channel in a direction away from the pilot combustionchannel.
 6. The burner apparatus according to claim 5, wherein thesupply line is provided in correspondence to each of the plurality offirst supply openings.
 7. The burner apparatus according to claim 5,wherein the fluid distributor is constructed such that the supply linescorresponding to the plurality of first supply openings are formed in aplate-like member disposed within the main combustion channel with itsplate surface oriented along the oxygen-containing gas flow direction.8. The burner apparatus according to claim 7, wherein the plate-likemembers of the plurality of fluid distributors are disposed with eachplate surface thereof oriented along the spiral direction of the maincombustion channel so as to act as a fin of a swirler for providing aswirling force to the supplied oxygen-containing gas.
 9. The burnerapparatus according to claim 1, wherein at a portion of the maincombustion channel more downstream than the first supply openings in theoxygen-containing gas flow direction, there is provided a swirler forproviding a swirling force to the fuel-gas mixture of theoxygen-containing gas and the fuel gas in the spiral direction of themain combustion channel.
 10. The burner apparatus according to claim 1,wherein the first supply opening is disposed, in the main combustionchannel, with an orientation for discharging the fuel gas toward moreupstream side of the flow direction of the oxygen-containing gas thanthe direction normal to the flow direction of the oxygen-containing gas.11. The burner apparatus according to claim 10, wherein the first supplyopening is disposed, in the main combustion channel, with an orientationfor discharging the fuel gas in a direction opposing to theoxygen-containing gas flow direction.
 12. The burner apparatus accordingto claim 1, further comprising a mixing promoting member against whichthe fuel gas discharged from the first supply opening into the maincombustion channel is collided to be diffused in the main combustionchannel.
 13. The burner apparatus according to claim 12, wherein themixing promoting member comprises a ring-like member disposed along theperipheral direction of the main combustion channel and having a plateface along the discharging direction of the fuel gas of the plurality offirst supply openings distributed along the peripheral direction. 14.The burner apparatus according to claim 3, wherein there is provided asecond shielding member for adjusting an inflow amount of theoxygen-containing gas, for the second gas supply area extending from theupstream side of the second supply opening in the flow direction of theoxygen-containing gas via the second supply opening of the pilotcombustion channel to the receiving opening.
 15. The burner apparatusaccording to claim 14, wherein the second shielding member comprises amember disposed across at least a portion of the second gas supply areaupstream in the flow direction of the oxygen-containing gas.
 16. Theburner apparatus according to claim 14, wherein the second shieldingmember comprises a tubular member which surrounds a portion of thesecond gas supply area.
 17. The burner apparatus according to claim 14,wherein the second shielding member defines an opening for adjusting theinflow condition of the oxygen-containing gas to the second gas supplyarea.
 18. The burner apparatus according to claim 5, wherein dischargingresistance of the fuel gas from each said first supply opening due topassage of the oxygen-containing gas is set so as to increase as beingdistant from the pilot combustion channel.
 19. The burner apparatusaccording to claim 18, wherein the setting of the discharging resistanceof the fuel gas is done such that a discharging angle for the fuel gasat each said first supply opening toward the upstream side in the flowdirection of the oxygen-containing gas in the main combustion channel isdecreased as being distant from the pilot combustion channel.
 20. Theburner apparatus according to claim 18, wherein the setting of thedischarging resistance of the fuel gas is done such that the dischargingdirection of the fuel gas from the plurality of first supply openings isset to be more upstream than the direction normal to the flow directionof the oxygen-containing gas in the main combustion channel and alsothat the opening area of each said first supply opening is increased asbeing distant from the pilot combustion channel.
 21. The burnerapparatus according to claim 1, wherein the first supply openings areconfigured to supply the fuel gas into the first channel along thedirection of the main combustion channel distant from the pilotcombustion channel; and a first shielding member is provided forpreventing inflow of the oxygen-containing gas from the upstream sidealong the flow direction of the oxygen-containing gas in the firstchannel, for a first gas supply area formed by the fuel gas suppliedfrom the first gas supply openings inside the main combustion channel.22. The burner apparatus according to claim 21, wherein a ratio (c/e)between a distance (c) between the opening center of the first supplyopening and the first shielding member defined along theoxygen-containing gas flow direction of the main combustion channel andan opening width (e) of the first supply opening defined in saiddirection is set to be greater than or equal to 0.5 and smaller than orequal to 1.5.
 23. The burner apparatus according to claim 21, whereinthe first shielding member comprises a member which extends in thedirection where the main combustion channel extends away from the pilotcombustion channel, one first end of the first shielding member on theside adjacent the first supply opening has a width (a) along theperipheral direction of the main combustion channel, the other secondend has a width (b) along the peripheral direction, the first supplyopening has a width (d) along the peripheral direction; and a ratio(a/d) between said width (a) and said width (d) is greater than or equalto 1 and smaller than or equal to 3, and a ratio (b/d) between saidwidth (b) and said width (d) is greater than or equal to 0 and smallerthan or equal to
 2. 24. The burner apparatus according to claim 21,wherein a hollow tubular fuel supplying member having a porous wallportion is attached to the first supply opening.
 25. The burnerapparatus according to claim 1, wherein said fluid distributor comprisesa distributing member which is provided in the main combustion channeland defines the first supply opening in its outer surface, and whichforms therein an oxygen-containing gas inlet duct for guiding theoxygen-containing gas supplied from the supply line and theoxygen-containing gas supplying means to the pilot combustion channel;and said distributing means includes, in said distributing member, asecond supply opening for discharging the fuel gas into theoxygen-containing gas inlet duct in a direction intersecting the flowdirection of the oxygen-containing gas inside the oxygen-containing gasinlet duct, a communication line for receiving the fuel gas dischargedfrom the second supply opening and guiding it to the first supplyopening, and a receiving opening for the communication line disposed ata position opposing to the second supply opening with a predetermineddistance relative thereto in the discharging direction, with thereceiving opening being open to the second supply opening.
 26. Theburner apparatus according to claim 25, wherein the distributing membercomprises a plate-like member disposed within the main combustionchannel with a plate face thereof being oriented along the flowdirection of the oxygen-containing gas in the main combustion channel.27. A fluid distributor disposed across three channels including firstand second channels through which a first fluid is caused to flow and afluid channel through which a second fluid is caused to flow, so thatthe distributor distributes the fuel gas inside the fluid channelbetween the first channel and the second channel; wherein thedistributor includes a first supply opening for supplying the secondfluid into the first channel, a supply line for supplying the secondfluid present inside the fluid channel to the first supply opening, anddistributing means incorporated in the supply line for distributing thesecond fluid into the second channel so that the distribution ratio ofthe second fluid to be supplied to the first supply opening is increasedin response to increase in a total supply amount of the second fluidfrom the fluid channel and conversely the distribution ratio of thesecond fluid to be supplied to the first supply opening is decreased inresponse to decrease in the total supply amount.
 28. The fluiddistributor according to claim 27, wherein the distributing meansincludes, in the supply line, a second supply opening for dischargingthe second fluid into the second channel in a direction normal to theflowing direction of the first fluid inside the second channel and acommunication line for receiving the second fluid discharged from thesecond supply opening and guiding the fluid into the first supplyopening; and at a position opposed to the second supply opening andspaced apart by a predetermined distance in the discharging direction ofthe second supply opening, there is provided a receiving opening of thecommunication line which opening as to be open toward the second supplyopening.
 29. The fluid distributer according to claim 27, wherein saidfirst channel and said second channel are disposed in juxtaposition, anda plurality of said first supply openings are distributed in the firstchannel in a direction away from the second channel.
 30. The fluiddistributor according to claim 29, wherein the supply line is providedin correspondence to each of the plurality of first supply openings. 31.The fluid distributor according to claim 29, wherein the fluiddistributor is constructed such that the supply lines corresponding tothe plurality of first supply openings are formed in a plate-like memberdisposed within the first channel with its plate surface oriented alongthe flow direction of the first fluid.
 32. A burner apparatus comprisingoxygen-containing gas supplying means for supplying oxygen-containinggas as the first fluid to the first channel and the second channel, andgas supplying means for supplying fuel gas as the second fluid to thefirst channel and the second channel, the first channel being used as amain combustion channel and the second channel being used as a pilotcombustion channel, the main combustion channel and the pilot combustionchannel receiving the supply of fuel gas for combusting it, theapparatus comprising: wherein said gas supplying means includes thefluid distributor according to claim 27 as a fluid distributor forsupplying the fuel gas present in the gas channel in distribution to thefirst channel and the second channel.
 33. A gas turbine engine includingthe burner apparatus according to claim 32 for rotating a turbine bykinetic energy of combustion exhaust gas exhausted from the burnerapparatus.
 34. A co-generation system including the gas turbine engineaccording to claim 33 and a heat recovery device for recovering heatfrom exhaust gas exhausted from the gas turbine engine in associationwith rotation of the turbine.